Is Trifexis safe? Are the internet rumors of Trifexis side effects true?

veterinary news

Trifexis Side Effects

Added December 2012: This article has collected a LOT of comments from people concerned about Trifexis side effects. I am torn on how to report on this issue. The fact that hundreds of you feel that Trifexis has been harmful to your pet is disturbing. However, if Trifexis is causing these serious side effects then I should be able to find a lot of discussion about this on places like Veterinary Information Network where tens of thousands of vets talk about their cases, and I am not.

If your pet has suffered Trifexis side effects then PLEASE have your veterinarian file a report with the FDA.  If there is a problem with the medication the only way the FDA will act is if they get enough reports of Trifexis side effects from veterinarians.

Original article starts here:

Trifexis is a relatively new heartworm and flea medication.  I have been prescribing a lot of it this year and it seems to be quite effective.  But recently I have heard a number of people on the internet complaining of possible serious Trifexis side effects.  So, is it true? Does Trifexis have serious side effects? Is Trifexis safe?

Is Trifexis safe?What is Trifexis?

Trifexis is a combination of two main ingredients.  The first is something called Spinosad which is the same flea killing medication found in Comfortis.  The second is called milbemycin.  Milbemycin is the same ingredient in Interceptor and Sentinel that is excellent for heartworm prevention and intestinal parasite control (hookworms, whipworms and roundworms.)

This year, Interceptor and Sentinel are not available because of a widespread shortage.  What this means is that many people who want to use an oral heartworm and flea preventative are turning to Trifexis.

The medication is given once a month along with a full meal.

Is Trifexis dangerous?

The following message is rapidly spreading via email and Facebook:

Fwd: hey…whatever you do…DON’T GIVE YOUR DOGS TRIFEXIS. HEARTWORM MED…jack is in the hospital..we tried trifexis for the first time yesterday (his interceptor has been off the market). and by 8 pm symptoms started…I had to take him in at 7 am..lethargy..confusion..tremors with a twitch every 15 appetite..he looks like he’s on an acid trip..his gut is drawn up…all symptomatic of called company …they admit some problems..will pay for blood panels on internal organs for toxicity reports but won’t pay for rest of treatment…so many people will be trying this drug due to not being able to get the discontinued interceptor or sentinel…tell all your dog friends… NO TRIFEXIS…EVER !

That’s a little scary, isn’t it?  But is it true?

Let’s look first at the information available on the Trifexis website in regards to Trifexis side effects:

Trifexis has been demonstrated to be safe in pure and mixed breeds of healthy dogs when used according to label directions for dogs and puppies 8 weeks of age and older and five pounds of body weight or greater. You should discuss the use of Trifexis with your veterinarian prior to use if your dog has a history of epilepsy (seizures). Puppies less than 14 weeks of age may experience a higher rate of vomiting.

Important point: Trifexis should not be used in an animal that has a history of seizures.  

Why is this? The makers of Trifexis don’t actually know if the drug is more likely to cause a seizure in an animal.  However, one of their test subjects did reportedly have a seizure shortly after taking Trifexis and so this must be listed on the label as a potential Trifexis side effect.  So far, in my practice, I have yet to have an animal have a problem with Trifexis (or Comfortis which also has spinosad in it) causing a seizure.

It is important to note that if an animal did have a seizure because of Trifexis, it would be most likely to happen within 1-3 days of administration.  If an animal has a seizure later on in the month it would be hard to blame Trifexis for it.

Some more information on side effects, from the Trifexis website:

Like all medications, sometimes side effects may occur. In some cases, dogs vomited after receiving Trifexis. If vomiting occurs within an hour of administration, redose with another full dose. During field studies, no severe or prolonged vomiting occurred. Additional adverse reactions observed in the clinical studies were itching, decreased activity, diarrhea, inflammation of the skin, redness of the skin, decreased appetite and redness of the ear. All reactions were regarded as mild

Well that sounds a little scary, doesn’t it?  But really, if you look at the list of side effects for almost any drug you will see that there is a great list of possible mild side effects.  What is listed here does not seem much worse than the possible side effect list for most other pet drugs.

The truth about Trifexis side effects?

Well, at this point, the truth is that we really don’t know if Trifexis is safe or dangerous.  As with any drug, there will be some animals that don’t tolerate it as well as others.  Is it dangerous enough that it is killing dogs and causing severe seizures?  I would guess, no.  But then, this is why I have written this article.  I would like your help in spreading the word and encouraging people to  leave a comment.  (We did a similar thing when people were complaining about side effects in regards to Kirkland dog food, and sure enough, shortly after I wrote that post and you guys responded with your experiences, a recall was announced!)

Remember, just because you read something on the internet, it doesn’t mean that it is true.  But, if enough people are saying the same thing then there may be some truth.  My goal is to take the information gathered from the comments in this post and put the data together to see if we can see any patterns.  If there is a problem, then something should be done.  If there is no problem, then Trifexis should not be given a bad name.

Have you been affected by Trifexis side effects?

Do you believe that your dog has suffered Trifexis side effects?  If so, please leave a comment below.  It would be helpful if you could include the following information:

  • Your dog’s breed and age.
  • What Trifexis side effects are you seeing?
  • How long after giving Trifexis did you see the side effects?

Thank you!  And please share this information with others so that we can determine the truth!

Dr. Marie.

Related: Trifexis overdose? My dog ate 4 tablets of Trifexis. Trifexis side effects.

If you feel that your dog has been adversely affected by Trifexis side effects, please have your veterinarian contact the FDA and file a report.  You can also either contact Elanco Animal Health at 1-888-545-5973, or report the problem to the FDA at 1-888-FDA-VETS or AnimalVeterinary/ SafetyHealth/ ReportaProblem/ ucm055305.htm    Trifexis side effects can possibly be serious but we are not certain if most of the Trifexis side effects reported in the comments are actually Trifexis side effects or perhaps something other than Trifexis side effects.




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Dr. Marie

Dr. Marie is a veterinarian treating dogs, cats, and pocket pets. Click here to ask Dr. Marie a question.

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803 Responses to "Is Trifexis safe? Are the internet rumors of Trifexis side effects true?"

  1. John says:

    I have a 3 yr old yellow lab named Carly. A rescue who had to go thru heartworm treatment before I could adopt her. I put her on Comfortis with heartgard plus when i found a flea on her. i liked the fact that I could use the Comfortis only during flea season. I did not like the fact that I was having her ingest a pesticide. She vomited on her second dose but otherwise, during the next 4 months she seemed fine. Always gave with a meal. This year the vet recommended Trifexis. Since it was Spinosad like Comfortis I thought all would be OK. Not sure I liked the 12 months of Spinosad AND since she gained a few lbs. (went from 58 to 62 ) her dosage of Spinosad doubled, and the heartworm med is different. Unsure exactly which it is, but I dosed her two months. Each time she was listless and ate less for about 72 hours. Took care of the fleas, though. Bottom line: got my money back on the remaining 4 doses and purchased Heartgard Plus and Frontline Plus. Why? If it makes my dog feel crappy for a few days it probably isn’t good for her and I’ll go with a topical.

    1. Anna says:

      My Standard Schnauzer, Zipper, is having issues standing and supporting his back end. His legs collapse underneath him when he walks. He had minor symptoms with his back end that progressively worsened. He is also having loose stools. His symptoms started started when he started taking Trifexis. I am having detox treatment done by my homeopathic vet. Will this side effect be permanent? I feel like I’ve poisoned my dog.

      1. DrMarie says:

        If this is an ongoing problem I would be much more worried about a possible spinal problem than a problem with Trifexis. Has Zipper been evaluated for possible IVDD?

        1. Debbie says:

          We started giving our dogs which are a 2-1/2 yr old Australian Shepherd, a 9-yr old border collie and a 1-1/2 yr old Havanese Trifexis a couple of months ago. We noticed no side effects whatsoever until time for the 2nd dose. I’m not really thinking these are side effects from the Trifexis though since all 3 dogs did fine @ first. Now only our Australian Shepherd is having problems with his hair falling out & getting flaky skin & bald spots. I’m just wondering if anybody else has experienced these same types of things with Trifexis. The only other thing we did different was give him a bath in Hartz whitening shampoo. I’m leaning more towards his skin & coat issues pertaining to this shampoo. I would appreciate any feedback on either one of these products causing the skin & coat issues.

          1. janet says:

            hartz made my puppy’s hair fall out too.

          2. Maggie says:

            Debbie , I have read that collies should not have the trifecious ( not sure I spelled correctly ) google it with collie in the search . I came across a few articles on it trying to see if it would be safe for my Maltese …I have decided to not use it after reading post by pet owners . It could have accumulative effect also on your collie so second dose may cause more harm than the first and there is some biological marker in collies that makes it especially bad for them. I read it in comments on a poodle rescue site . Good luck

          3. DrMarie says:

            Collies are not more sensitive to Trifexis than other dogs. Trifexis does contain milbemycin, which at a high enough dose could affecte a Collie, but the dose in Trifexis is extremely small. Here is more information:

          4. Jeanine says:

            I gave my mixed breed 6 year old dog Trifexis and had similar problems. She was disoriented and lacked appetite after the first dose. After the second dose, she was staggering around the patio and couldn’t seem to focus. Shortly after, she began losing her hair and became scaly and smelly. We went back to Heartguard after that. It has been three months since that second dose and she still has significant scaly patches on her ears, rear, and tail. It seems as if the treatment has worked its way down her body and to her extremities. She normally has an abundance of hair, similar to a St. Bernard. At this time, the hair on her chest and stomach is so sparse that you can see her spotted skin and one part of her tail is completely bald. Trifexis is the only thing in her life that was changed so I definitely blame it for her problems. We have another dog that did not take Trifexis and he has none of her symptoms, so we know that it is not a mite or other parasitic skin disorder.

          5. Christalina says:

            Yes….the same thing happened to my black lab. His skin was filled with irritation, bald spots. He was loosing hair faster than ever and he didn’t eat much. I have since taken him off Trifexis and wondering if I should just go back to heart guard and topical flea and tick. I feel like his system is finally back to normal and it been at least 3 months since the last does of trifexis

          6. Jane Fredericks says:

            We have an eight year old sheltiie who has been having undiagnosed problems of patches of flaky skin where the hair falls out in patches and the skin is irritated. We have been to two vets, had her on antibiotics for approx. 3 weeks with no improvements, also a spray medication, no improvement. So glad we read this site and feel that Trifexis could very well be the problem, we will definitely stop using it and hopefully the skin/hair loss problems will get better!

          7. Marcia says:

            My two goldens were given this used to use sentinel and that other one that was discontinued. So vet gave me this. They have horrible dry flaky skin and hairloss scary my beautiful goldens

          8. Becky says:

            I just gave my 15 month old Aussie her Trifexis and about 1 hr later she threw up. She has been on Trifexis for about 7 months, but last month the same thing happened. So now I believe that Trifexis is making my poor dog sick as soon as she takes it. She is very tired now also. Now I have to decide what to give her!

          9. Donna Sonne says:

            I have a four year old Spanish Water Dog that is 55 lbs. I have given him Trifexis for the past two months. He has several bald spots, his hair has fallen out in areas and the rest of his hair is growing very slowly. His skin and hair have darkened in spots across his back. Our vet is taking the medication back and we will go back to Frontline & Heartguard. I wonder how long it will take for his coat to be back to normal.

          10. Penny says:

            My Australian Shepherd is about 6 years old and isn’t feeling well from the Trifexis. I gave it to him yesterday with his supper. He is very blah. Didn’t want to go on his walk in the field. He is groggy and of course the vet is closed for the weekend.

          11. tammy says:

            I gave my English bulldog trifexis for three months the hair started falling out in-between her should and neck. I thought it was just her collar rubbing because I kept it pretty lose. Then her hair began for fall out of her chest. She also began shedding really really bad. The shedding has never been this bad. Lucy also doesn’t act as perky as usual either. My advice is to take your dog off the trifexis and try something different. Lucy’s’ hair just doesn’t seem to want to stop shedding. Good luck.

          12. Lacey says:

            I have a three year old boxer APBT mix named Belle. I rescued her six months ago. I have all of her prior vet records and she was always a healthy well maintained dog. i found a flea on Belle one day and decided it was time to get something. I bought Sentry brand topical. She was deathly sick. my hyperactive dog wouldn’t eat, drink, or get off the couch. she had such bad diarrhea that she would leave a trail as she would try to make it to the door to go outside. I washed her with Dawn in the tub once i realized what was happening. She still had fleas. They itched her so badly she shook her ears to the point of giving herself a hematoma. When i took her to the vet they suggested Trifexis. When we got home I administered the pill. no problems. She was till itching like crazy so i bathed her. I use Richards Organics. Sometimes i will use Avoderm. I am always sure to use tepid water and remove all soap residue. I also change and wash her bedding at the same time. I gave her the Trifexix two weeks ago and she is itchier than ever, like so itchy i cant even reach my hand out to touch her, as the thought makes her start scratching. its all she does, scratch and chew. She scratched herself bloody in the night last night which is what led me here. she is also now missing the hair on her thighs and buttocks. its thinned everywhere else as well that i can see her scaly red skin. she has little bumps everywhere like big hives. Poor girl is miserable. she was better off with the darn fleas.

          13. Lacey says:

            I have a three year old boxer APBT mix named Belle. I rescued her six months ago. I have all of her prior vet records and she was always a healthy well maintained dog. i found a flea on Belle one day and decided it was time to get something. I bought Sentry brand topical. She was deathly sick. my hyperactive dog wouldn’t eat, drink, or get off the couch. she had such bad diarrhea that she would leave a trail as she would try to make it to the door to go outside. I washed her with Dawn in the tub once i realized what was happening. She still had fleas. They itched her so badly she shook her ears to the point of giving herself a hematoma. When i took her to the vet they suggested Trifexis. When we got home I administered the pill. no problems. She was still itching like crazy so i bathed her. I use Richards Organics. Sometimes i will use Avoderm. I am always sure to use tepid water and remove all soap residue. I also change and wash her bedding at the same time. I gave her the Trifexix two weeks ago and she is itchier than ever, like so itchy i cant even reach my hand out to touch her, as the thought makes her start scratching. its all she does, scratch and chew. She scratched herself bloody in the night last night which is what led me here. she is also now missing the hair on her thighs and buttocks. its thinned everywhere else as well that i can see her scaly red skin. she has little bumps everywhere like big hives. Poor girl is miserable. she was better off with the darn fleas. Not sure where to go from here

          14. Lacey says:

            I have a three year old boxer APBT mix named Belle. I rescued her six months ago. I have all of her prior vet records and she was always a healthy well maintained dog. i found a flea on Belle one day and decided it was time to get something. I bought Sentry brand topical. She was deathly sick. my hyperactive dog wouldn’t eat, drink, or get off the couch. she had such bad diarrhea that she would leave a trail as she would try to make it to the door to go outside. I washed her with Dawn in the tub once i realized what was happening. She still had fleas. They itched her so badly she shook her ears to the point of giving herself a hematoma. When i took her to the vet they suggested Trifexis. When we got home I administered the pill. no problems. She was still itching like crazy so i bathed her. I use Richards Organics. Sometimes i will use Avoderm. I am always sure to use tepid water and remove all soap residue. I also change and wash her bedding at the same time. I gave her the Trifexis two weeks ago and she is itchier than ever, like so itchy i cant even reach my hand out to touch her, as the thought makes her start scratching. its all she does, scratch and chew. She scratched herself bloody in the night last night which is what led me here. she is also now missing the hair on her thighs and buttocks. its thinned everywhere else as well that i can see her scaly red skin. she has little bumps everywhere like big hives. Poor girl is miserable. she was better off with the darn fleas. Not sure where to go from here

          15. Selena Coles says:

            I gave my 3 year old pit bull Trifexis after being told by my vet it will not wash off. He did fine til dose 3. He broke out in hives. I gave him Benadryl, and he was fine in a couple of days. Dose 4 he did the same. By dose 5 he has lost hair around his belly, rib cage, and under his front legs. Worse are his feet. He is literally chewing the hair and skin from around his pads and nails. I will be switching back to Heartguard Plus and Frontline or Advantage.

          16. Bonnie says:

            I have a 4 year old long haired mixed baby. I gave her a trifexis on 6/18 she has progressively lost more and more hair. At first it was the scratching then her hair started to mat and I gave her a bath in oatmeal shampoo for dogs. Now she has little hair around her neck and head and the sides of her body are beginning to lose hair as well. Her skin is hot and pink…I kept thinking it was laundry soap, or something else, but everything is pointing back to the pill. I plan to take her to her doctor this week.

          17. Kim says:

            I gave my 6 year old Boxer Trifexis his dose 3 days ago. His hair is falling out like crazy. I am taking him to the vet in two days. This HAS to be a side effect. Needless to say, I am NOT happy!

          18. Kim says:

            I gave my 6 year old Boxer his Trifexis dose 3 days ago. His hair is falling out like crazy. I am taking him to the vet in two days. This HAS to be a side effect. This is the 3rd time he’s had this medication and he didn’t have this problem before. He has thrown up though. I knew this might be a side effect, but never in a million years did I think I might be poisoning my dog! Needless to say, I am NOT happy! We need to get this medication OFF OF THE MARKET NOW!

          19. Jenny says:

            After the 1st dose of Trifexis my dogs hair started falling out as well as severe itching along with lovely diarrhea. It was without a doubt from Trifexis because the same happened with my cousins two dogs. Was it a coincidence that their hair came back in when she stopped using it. I don’t think so! All the best to you and your pup.

          20. Y Berry says:

            We have a 2 year old mixed breed and a 4 year old chihuahua/rat terrier. Both dogs got blisters filled with what appeared to be puss within a week of taking trifexis. The 2 year old also had bald spots on his back. We switched to heartguard and bald spots and blisters have subsided.

          21. Jeff says:

            I have a almost three year old Australian Sheppard/Chow Chow Mix. He has taken Comfortis and Heartgard since I rescued him last November. I decided this month to switch to Trifexis. He received his first dose at breakfast on the 15th of July. I put the pill in with the rest of his food and it is eaten along with the rest of his food during that feeding. I have noticed slighlty more itching but nothing extreme and I have noticed, last night especially, that during his brushing there was quite a lot of hair consumed in the brush. It is shedding season though, so I’m unsure that this is a reaction to the medication. I will continue to monitor my dog and he also has three days a week spent with his personal trainer and some other dogs that do day care as well. Good socializing and excellent time spent with a trainer. As far as Trifexis is concerned, just like any other medication you have to monitor your dog and observe things that are unusual for your dog. Make sure he/she is not getting into other things that could cause bad behavior or mischief that could lead to what appears as adverse reactions to the medicine.

          22. Kathy says:

            I have seen a number of people say their pets experienced hair loss and flaky patches after taking Trifexis. I have a 5 month old English bulldog that took three does of Trifexis. He vomited three hours after the third dose. After the second, dose, I noticed a bald spot on his leg. His Vet prescribed an antibiotic for staph. After 28 days on the antibiotic, we returned to the vet with many more bald spots on his legs, and all over his head. The vet did a skin scraping and diagnosed Demodex, mange mites. He put my puppy on Goodwinol, but the condition only worsened. Two separate vets have suggested Ivermectin, however, there are serious risks if using Ivermectin off-label while on Trifexis. Has any one else had a diagnosis of Demodex after using Trifexis?

          23. Bandits Mom says:

            We started Bandit (7yr) Beagle on trifexis two months ago and three days after he started the first dose I noticed funky bumps under his hair then the hair fell out, I thought it was a bug bite until I found mulitples on him. Near the end of the month the bumps were subsiding but once he had his second does, WHAM bumps again and hair loss, he is going to the Vet Wednesday and I’m going to get him onto some other type of prevention.

          24. Lorena Gamboa says:

            Hello, Debbie, my doggie niece Coco has had a lot of issues with keeping a nice coat. I think this could be due to the side effect warned by Triflexis — pruritis, which is itching. Coco itches a lot on the sides of her body right before the hips. She bites herself a lot because it seems to be a very itchy spot for her. We cannot think of anything else that it can be. I have been eager to mention to my sister that Coco might be suffering from the side effect warned by Triflexis. This is what I think could be a very big likelyhood. First, I am taking the time to read online about other people’s experiences in order to more fully provide my reason for thinking that this issue with Coco’s hair loss is due to the intense itching. I have been really thinking about what it could be, and I really think it’s the Triflexis causing Coco this particular side effect. What else? She is an 8-year-old English Creme, long-haired (not anymore), miniature Dachshund. Now that I see you’ve been having this issue, I do agree it’s very likely culprit. Terrible side effect if, in fact, it could be proved. My sister is very puzzled and disturbed to see her doggie go through that. I hate to see it too. I need to tell her to keep watch each time they give her a new dose to see if they notice the itching to be more intense. Thanks for sharing your story, Debbie. I am sorry to learn you’ve had these troubles. I have two of my own. Whenever anything goes wrong, I just about lose it. Best wishes to you and your doggies!

          25. Wendy says:

            We have a 6 month old German Shepherd. He has been given trifexis since 8 wks old and since that time has had ongoing skin irritation that results in biting and scratching of back, paws – just about everywhere. After reading the package insert and these blogs, I have decided to stop the trifexis…he is due a dose next Monday – to see if the condition is corrected. I also notice that he has episodes of vomiting and diarrhea for a day or so after each dose. Unfortunately, last month I purchased a six month supply of Trifexis, which is not cheap! It also came with a rebate offer which, after several tries and even a call to the company, I still can’t access. So, guess Trifexis was just a very expensive mistake on my part! I wish I had done more advanced research, but was relying on the reader’s recommendation. And she can’t really be faulted as it seems not much is known about side effects of this product.

        2. Barbara says:

          Our 2 Boxers have been taking Trifexis since December 2011. Each of them have been showing signs of weakness in their back ends. When they walk, their back legs slide out from under them. It’s as if they have no control over their back legs. One dog is worse than the other. They are not related, by the way. We’ve had them checked for hip problems, but that’s not the problem. I’ve told our vet about our concerns and have switched them to Heartguard as of this month. Do you have any suggestions?

          1. erin says:

            Barbara – my boxer passed away from myelopathy at 10 yo and that was one of her first symptoms. I think its common in boxers and you might want to check it with your vet.

          2. Very Concerned in Puerto Rico says:

            We gave our little dog (5-9lbs mixed breed) one dosis of trifexis and within hours began to be lethargic and can not keep on her feet. When she stands up, after a few steps, her back legs are the first to give out. And she has a blank stare. Will the sypmtoms subside? How long will it take?

          3. Sarah says:

            I have an 8 yr old pug and a few hour after giving her a dose of Trifexis, she was unable to support her own weight and seemed very disoriented. It took her several hours to return to normal. Also, I have given it to my Pit bull who is 4 yrs and it makes him very “doped ” and sick for 2 days following the dose. I am discontinuing the Trifexis.

        3. Jennifer Bailey's Mom Ft Worth, TX says:

          Bailey is a 6 year old pure breed West Highland White Terrier. She weighs about 17 lbs. We just moved to Texas from Chicago, IL. This is the second month I have given her Trifexus only to have uncontrollable vomiting for more than 12 hours each time. The first time, the vet took her in and gave her fluids for almost a whole day plus anti-nasea medication. They asked me to give her half of a Priolosec this time before administering the dosage. But, my dog is vomiting again all night. The symptoms don’t start immediately but rather about 8-10 hours after the dosage. This is very, very concerning to me as both times my dog is clinging to me like a child and letting me know she feels very very bad by tucking her nose under my arm to hide her eyes. She has thrown up at least 5 times already and the vet doesn’t open for hours. We have always used a private practice vet in Chicago but have recently gone to a chain pet store’s vet. They do not offer her regular heart worm and flea med. So, they switched us to Trifexus. The results are excessive vomiting and shaking and dehydration so far at a minimum. This is not acceptable. Please do not give this medication to your pet without watching them closely for 24 hours after dosage. Bailey will NOT be taking this again.

      2. Matt Baker says:

        My puppy experienced the exact same symptoms after I gave him a single dose of Trifexis. He is a 14 week old German Shepherd. I will never give him another dose. What is the detox treatment??

        1. Katlyn says:

          Keep in mind that puppies when normally receiving trifexis have also just gotten their puppy shots. Our first time using trifexis with our 18 week old lab she had diarrhea and some vomiting because we hadn’t followed the instructions on making sure she had a full meal before taking the medicine. The 2nd time she was perfectly fine. And this time she is lethargic because of all the different vaccinations she received today along with trifexis. The vet said she will be lethargic and lose her appetite. My vet also told me to not worry about what people say on the Internet because it is a case to case basis. In some cases he said adult dogs will have seizures or allergic reactions because they are switching medicine that they have used for years. They say you see a lot less side effects in puppies.

          1. Kathy says:

            I have a 13 week old puppy and my vet gave him Trifexis on Saturday. Six days later( Friday) this week he had a seizure. I thought he was dead because my husband found him stiff in his cage then when I picked him up he went limp. As we rushed to the vet, he started to come to. I was so scared. The vet asked did we have rat poisoning around the outside, but we keep our puppy inside the house and no we do not have rat poisoning outside. He didn’t eat any poisonious leafs or plants and he has been fine. They did blood work and everything came up normal. As I searched the internet for answers this is the conculsion I have found. As from the breeder none of her dogs or puppies have seizures. So I would NOT recommend Trifexis to anyone. My puppy will not get anymore doses.

        2. Candace says:

          My 15 month old French Bulldog became blind on Sunday, it is linked to Trifexis. She has been on it for 12 months. Please don’t use this drug. Mu nephews dog had siezures and died last year and I just found out he was on the same drug. UC Davis Vet Center had linked it to the drug.

          1. Brandi says:

            My french bulldog Rosie, just went blind on Saturday…..She was given a dose of Sentinel on Monday. Not sure if this is linked yet or not…but wondering if your french bulldog recovered or is the blindess permanent?

          2. sandra says:

            My dog is 5 years old and is going blind in his right eye, which I thought was way too early. I have have given my dog trifexis for 2-3 years. He is pretty lethargic also. I now wonder if this flea med has an effect like what my dog is going thru that is very harmful.

      3. Dana says:

        Anna – My vet thought we were crazy when we told him that we thought Trifexis was causing our dog to limp. It was about his second or third dose when he started limping with his front leg. He had trouble with his back knees in the past, but never the front. The vet could not figure out what was wrong and gave him pain medication. At the same time, we started to see fleas on him and wanted to try going back to a topical flea treatment. Within a couple of weeks of going back to the topical flea treatment, the limp mysteriously stopped (and so did the fleas). I was happy at the prospect of not having to use a topical treatment since we have a young son, but not at the expense of my dog limping and having fleas. I can’t prove the Trifexis caused the limp, but it certainly is an interesting coincidence that it started and stopped with the Trifexis.

        1. Nicole says:

          My dog was switched from Revolution, which she tolerated well for over a year, to Trifexis in December 2012. She is a Pembroke Welsh Corgi and just turned five years old on February 8th. Since switching treatments, she has had sensitivity to touch (groaning when we rub her side or belly) and two bouts of horrible hot spots on her vaginal and rear hind leg area. I currently have her in a cone after another cortisone shot and oral antibiotic for yet another infected hot spot. Normally, she is quite energetic and healthy, but she has been demonstrating marked lethargy over the last 30 days. In addition, and like another commenter, she has developed a limp in her front right leg. The ONLY thing that has changed in her routine is Trifexis so I am inclined to take her off. Does anyone recommend a good detox treatment, and should I give her two to three months before I resume Revolution so that she can get this pesticide out of her system? I live in Southern Cal, and we are approaching the height of flea season so I am concerned. Lastly, I have an appointment with her vet Monday because I would like him to file a report with the FDA on this medication.

          1. corgiowner says:

            Just wondering how your Corgi is doing and whether she is doing better off of Trifexis? Curious what you switched to (for heart worm) as I am thinking of doing the same after reading these comments.

          2. Kathy says:

            Our 10 year old Pembroke Welsh Corgi had similar side effects as everyone is mentioning. We noticed it after his 4 th dose of Trifexis. He was extremely lethargic, grimaced with any touch, lost his fur, skin had a foul odor,could not stand on his hind legs (even to go outside) and would not eat. Our usually happy, excited Corgi would not even come out from under our bed to celebrate Christmas! He was usually the center of attention. My vet still thinks I was crazy for suggesting that it was related to the Trifexis. When I called the manufacturer, they said that ” it definitely sounds like a reaction” and offered to refund my money. Since I purchased the medication at through my vet, my refund came through them. They did not seem the least bit happy or interested that I called the company and was getting a refund. Needless to say, we are changing vets. Now, 5 months later, my Corgi is more his usual self. All of the effects have subsided, with the exception of the skin issues. I think that this is poison and I won’t give it to any other animals. I will say that perhaps, it’s not the kind of medication that will work with such wide weight categories for dosages, given the combination of medications. My Corgi was dosed based on his weight, but his body/ organs are not the same size as those of a larger bread weighing the same amount.

      4. Richard Soltys says:

        I had a chi/min pin mix who dad the similar problems with the lehs and than started having seizures. Shortly before he lost his sight. I got him froma shelter and they gave him a clean bill of health . After starting him on Trifexis he went downhill. I feel so bad thinking that I killed my dog.

      5. Kimberly says:

        Anna, how did your dog do after detox? Did the balance in his hind legs improve? My dog has had major balance and coordination problems and he was just diagnosed with cerebellar degeneration at only 1 year old! I have just put it together that Trifexis might have caused this, and then I go out to research it on the Internet and find other people are going through the same thing. Please let me know if getting your dog off Trifexis and doing detox made any difference in his hind leg weakness.

      6. Kimberly says:

        Anna, how is Zipper doing? Did getting off Trifexis and doing detox make a difference? My dog is experiencing these same symptoms. Any feedback you can provide about how your dog is doing would be appreciated!!!

      7. Kay says:

        Anna, what has happened to your schnauzer since you wrote this post? I have a one year old dog that is taking Trifexis and is also experiencing hind limb ataxia and head tremors. I have seem a veterinary neurologist, and she did an MRI and a spinal tap. She told me that my dog has symptoms of cerebellar degeneration. However, he has also had blood work done that indicates he has some liver issues. I am wondering if the Trifexis injured his liver, which in turn injured his cerebellum. I am going to see a holistic vet next week. After your dog went thought detox, did the hind limb weakness improve? I hope you see this post. I am pretty much grasping at straws here.

    2. Dawn cervenka says:

      I have just given my 1 year old LAb mix trifexis and now know that symptoms I’d observed previously are definitly caused by this drug. The first time, I had not reason to suspect the drug and it actually fell of my radar, second time I knew it was the drug. My vet assured me that unless Janx was physically I’ll, throwing up, there was no problem. They also said that lethargic behavior was NOT a symptom. wrong!,,, the third dose wasmjustbgiven and within 2 hours jax is huddled in his bed and can’t lift his head. I have called the er and they confirmed that trifexis definitlyn causes these symptoms. They felt I should bring jax in for fluids to flush his system. I am so torn between spending 350.00 or waiting until morning to see if he is fine ( this was the case the last two times) ! I am so mad at my vet for not being more aware of the drugs issues and confirming versus disagreeing with my observation!!!!!

      1. Don says:

        Same problem as most replies describe. I gave my 16 week old Golden Retriever his first dose of Trifezis last night with dinner and by this morning he was lethargic and could not stand up on his own due to weakness in his, twenty hours after the dose he is more alert. Will not be using the product again.

        1. Kelly says:

          I found this site because my shih tzu was having mucousy poop and some vomiting after giving Trifexis. I tried giving her half a pill two days ago and was going to give her the other half the next day but she is having the mucousy loose poop again. I’m taking the Trifexis back to the vet and switching to heartguard!!

    3. Deborah says:

      I’ve given my 12 yr old dobie mix 2 doses of Trifexis (she was on Sentinel) both times with evening meal. So far haven’t noticed any side effects.

      1. Sue Barrass says:

        Our 2/12 year Ole English Bull dog has been on Trifexis for almost 1 1/2 years. She is pretty listless for about 12 hours so we give it her at night and she is fine in the morning.

      2. cindy says:

        I had my three dogs on front line plus and heart hard for years. They hated getting front line and would literally run when they saw it. Then we got fleas that would not die. I had some advantage from another time front line quit working and applied it to my two small dogs. It only worked on one of them. After speaking with vet he recommended trifexis. My rat terrier and my German shepherd loved them but I had to force feed the jack Russell. I made sure to feed them something they would eat immediately. Lo and behold there are no fleas. My dogs have been on this two months with no problems. I too am nervous about internal meds for fleas. This is why I am reading this because we now have small puppy an worried about putting her on this. My other dogs are 13, 5, 3. I think I will keep other dogs on this and put puppy on topical with heart hard after reading this.

        1. Maria says:

          Gave trifexis for 1st time to my 8month old Lab Shepard because because I’m broke and the vet gave me 1 dose sample free. Read the info on tap, my BO weighed in at 40lbs. today that is a gain of 2 lbs. since she found me during the January freeze in San Antonio Tx… She lives to run. Fed the Trifexis in a peace of raw chicken breast which part of her raw diet and the last 8oz. meal of 2 daily. I ran a search on Trifexis to find all the horror stories here. I will be sleeping with my dog tonight.
          Information on the tablet tap specifies minimum weight of 5lbs. – max of 40 lbs. body weight, 8 weeks minimum age, there is a lot # and Expiration Date of 03/2015.
          I gave BO Trifexis because I’ve seen her eat feces, wood branches, dirt, stuff she sniffs out off the ground. I’m learning to read when she is instinctively just hunting and when she is getting ready to eat some garbage to correct the “Bad Eat” behavior. BO plays almost everyday at the dog park with other big dogs for a minimum of 15 minutes included in 3 daily walks that last at least 45 minutes to an 1hr. each. I will not feed her commercial dog food or treats anymore than I eat commercial process foods, as much as, under my control.
          Same goes to the environment conditions I will expose myself or companion to. I fumigate the yard and don’t let BO out there for days, not the best option but its what I do. I’m looking to select exercise or play time companions with dog owners I come to know as armed with knowledgeable information resources & experience because I need to learn more for my pet & I to protect our health and survive FDA oversights of unscrupulous profiteers and captains of commercialism or just have been drinking too much of their own kool-Aide.
          If your companions are more indoor than out door pets avoid injestible medications whenever possible. If your dog’s heartworm or other worm tests are negative don’t medicate. If you have a small breed family member, what is the weight recommendation on the tab of Trifexis or whatever, pet injestible pesticide you choose and adjust the dosage by cutting the tablet into 4 1/4s or whatever size would be more appropriate for you dog’s weight.
          I’m researching natural spice and dietary alternatives to worm & pest infections prevention among breeders, other dog owners’ forums, its all very controversial and difficult to find the right course of action.
          Its been 4hrs. since I administered the Trifexis, BO is asleep now. I will not be using this product or any injestible product for my dog’s flea control for this I will seek perhaps a topical solution or preferably a natural solution and continue to fumigate the back and front yard. For heart worm and other worm infection prevention I will experiment with apple cider vinegar as a dietary supplement along with periodic fecal tests. Check the following for more info. Thank you all for your experience and my condolences on your companion’s & your suffering.
          Hope Trifexis works for my BO this one time and if it does I would only use it for worm infestation which I hope to prevent without toxic medications, this has to be the last resort. I will report back here should any ill side affects manifest.

    4. M McAlpin says:

      I was wary of Trifexis when we had to discontinue Sentinel for our 12 yr old mixed breed. But vet’s confident attitude convinced us to try it (“if he vomits, just give him another one; if he continues vomiting, discontinue & return the meds and we’ll find another treatment for HW and fleas”). He didn’t vomit after dose #1, and the first month we only noticed his appetite was off, maybe a bit lazy after dosage. We were worried b’c he was at the cutoff weight (60 lbs) btw two diff dosages, but vet tech assured us the higher dosage was the right way to go. We gave him the second month’s dosage yesterday and had to be out for the evening: we ret’d to an unrecognizable dog. Disoriented, unable to move easily, would not eat, could barely walk. He does have arthritis, so we thought maybe Trifexis just made him “lethargic” and prolonged sleep left him achy. We gave him a Rimadyl and ordered more Adequan this morning, which we give him at home in an injection. Appetite cont’d all day to be nonexistent, eyes show pain or disorientation, just not himself. Now I’ve read all these postings and I’ve got to wonder if the mobility issues and lethargy we are seeing were neurological, a side effect of Trifexis! He seems better tonight and ate dinner with the incentive of a little “tuna juice” poured on it. We will never give him Trifexis again, but don’t know what we will give him, and don’t know whether this seeming upturn means he is OK or we should have him checked anyway? We had no problems on Sentinel, ever. Why do consumers have so little info and power in regard to these very expensive drugs we give our dogs (ie, loved ones)? Vet opinons are as varied as info on the internet. We have no idea where to get a definitive opinion. Reading anecdotal stories online seems like a poor research method, but where else can we turn?

      1. Natalie says:

        I have a 7 year old mixed breed border collie and German shepherd. She took the pill 2 weeks ago and hasn’t been the same since. Went to the vets multiple times. Couldn’t find an answer. Finally today we did Iv on her to see if it was any better. Turns out not that much. She’s lethargic and not the same. The doctor finally got to observe her for the whole day and she thinks its neurological. My dog has had several accidents, lethargic, and just not her plain energetic self. We will see if the drug can wear off in 6 weeks…..if

      2. G.oknzi says:

        Google Rimidyl. My yellow lab had permanent kidney damage after use. My vet gave me no idea the potential side affects.

    5. Yvonne says:

      We have a 3.5 year old llewelyen setter weighing about 60 pounds. In the past we tried Comfortis once. Afterward she was practically comatose for several hours so went back to the topical treatments. The fleas have been terrible here where we live so this summer we decided to give Trifectis a try with mixed results. We have given her about 4 treatments. Twice including last night after giving her the pill with a meal, she has had similar reactions – disoriented and anxious. Kept us awake with pacing, standing by our bed, panting, funny look in her eyes. That caused me to check out this site this morning. After two bad reactions, we will not use this product again even though it is very effective for flea control. She ate only a little this morning but otherwise seems ok now.

      1. Jim says:

        We have an eight yr. old golden retriever mix, who has only had medication for ear problem 2 yrs. ago… So we took him to the vet in Nov. for skin problem and was put on trifexis…He had his 2nd dose Jan. 1…Now he is not the same dog and we are sick…He is also panting, pacing, making noises, standing at the bedroom door until we let him outside for the night…He has never slept outside all night before this..Our yard is fenced, but it was 20 degrees last night, so I put him in the back bedroom and shut the door..I believe he cried all night, so got up at 5am to let him out..He came out of the bedroom all confused and we are at our wits end..Going back to vet in Feb. after this pill wears off…we can only hope he gets back to normal…No more trifexis for our dog!

      2. Jules says:

        If your dog reacted to Comfortis, it should have never been given Trifexis. The same flea agent, Spinosad, is in both. I believe after thorough research it is a dangerous poison.

    6. Lee says:

      I gave my 70 lb. greyhound trifexis yesterday. He was lethargic all day yesterday, & today had extremely bad diarrhea. Trifexis was the only variable in his day, so I’m fairly certain that it was the trifexis.

      1. LauraH says:

        Lee, I was wondering if the diarrhea your dog experienced got any worse? Ours certainly did!!

    7. salli says:

      Trifexis is horrid! I have a 5 year old perfectly healthy (once) Havanese. I gave her one dose of Trifexis, she has been going through hell! Diarrhea, weight gain, not drinking water, lethargic, and now they are testing her for Thyroid problems. Everything was perfect in her August chem panel. Started Trifexis mid November… and still trying to get my darling healthy dog back. Vomited only once four hours post Trifexis, lethargic and a bit twitchy. Then the not wanting to eat started followed by colitis looking stool, bouts of diarrhea, and now less than a month later, she is panting, has the runs, acts like she has urgency and then pure liquid Fecal matter. She had perfect stools before this. So far I am at 1000.00 and counting post Trifexis… DO NOT GIVE YOUR DOG THIS DRUG!

    8. Teresa says:

      I have a 9 year-old Shiba Inu. I got Sheila from the shelter and take her there for her veterinary care. She takes Trifexis every month. I coat the pill with peanut butter because she loves it which makes it easy to get her to eat it. I have not noticed any adverse reactions whatsoever since she started taking this medication.

    9. Cate says:

      We have been giving triflexis to our 2 year old Goldendoodle for about 18 months we have had no problems at all and in fact he tolerates the medication better than he seems to tolerate topical flea products.

    10. Scary69 says:

      I have been using Trifexis for over a year on my Toy Poodle and he has had NO side effects. Like it was stated in the article depends whether the pet has has health issues in the past and not all medication will work the same on all pets. Even adult medication does not work the same on all adults, does not mean I will not take it because everyone is different.

    11. Rose says:

      Have 3 dogs, only one moved to Triflexis. 3 year old healthy yorkie cairn terrier mix-9 lbs. Lethargic after first dose – not enough to worry but stuck in my mind. After 2nd dose, effects lasted longer that we thought she might be ill with something else – lethargic, skittish, licking, spacy and sometimes yelp for no reason. Took to vet – thought it was back injury but no real evidence. Steriods, pain killer, muscle relaxer. By third dose, more of the same, took to another vet who “guesses” the same and bumps up medicine for the 3rd time. After more rapid decline, increased spasms, increased difficulty standing, runny nose, spot on lung and ineffective posturing, took to neurologist specialist. She’s in hospital now, decreased platelet, anemic, increased liver enzymes. Systemic conditions masked by Steriods. All vets supposedly did X-ray and full blood panels. I suspect Triflexis has played a bigger role in all this. Wanted to post this in case others are being directed down the back injury route – please get your pup to a specialist if your vet is just guessing if they are exhibiting neurological effects after taking Triflexis. I hope we have made the right move in time – my baby will not get another dose.

      1. Misty says:

        Seriously, my dog has been fighting this SAME thing since January–for 7 months now. But his reaction was to a different topical flea medication with permethrin as the active ingredient. His platelets got so low he had a brain bleed stroke–and has spent the last 3 weeks recovering from that. I tried Trifexis about 2 months ago and he slept the whole rest of the evening. Too scared to give it to him-but my vet says that should be ok to give. I decided to research it BEFORE I give it to him this time–and I am just about sick! I feel like everyone else –guilty for giving this to my dog and he has had a stroke as a result. I know now that I will NOT give him this again—or any other for that matter. 2 different meds with the same issues-I am not trying a 3rd. I think I am going the “natural” way.

      2. Stephanie says:

        Rose, can I please contact you via email? My dog, Baci, was suffering from the exact same symptoms you describe before her red blood cell count dropped to numbers she could not handle… symptoms started with lethargy, unexplained shaking, and she was prescribed steroids to deal with a supposed slipped disc in her back. We had to put her down in October after two blood transfusions and no recovery. I would love to talk to you as her case was never resolved, and until now, I never suspected Trifexis–which I had switched her to a few months previous to her symptoms. Thanks.

      3. Carrie says:

        My precious yorkie has has very similar experiences. I am scared we will lose her. This med has killed over 700 dogs, so far! What more proof do people need? I just signed a recall petition on I pray they Stop this killing spree.

    12. Lori says:

      For the dog owners on here who have had a dog react to Trifexis, my 70 pound pitbull is currently going through this. I have been home with her all day trying to help her. Any advice on helping her get through this? I am so angry I did not research this drug before taking my vets advice to switch my girl to it. I am upset that a decision I made had put her through this. She is an otherwise very healthy and tough dog. This is the first time she has ever had anything like this happen to her. How long will it last? Will the vet be able to do anything for her if I bring her in? I am growing less and less trusting of my vet and am in search of a new one.

      Symptoms: trembling bad every time she breaths in, disoriented, wobbly when trying to walk, she has fallen over several times, trouble using the bathroom, very sleepy, eyes are low (not opened all the way), she has vomited twice and has not eaten all day which is a first in her 8 years of life. When I put her food down this morning, she would pick up pieces in her mouth, then spit them out… at first I thought it was a tooth problem but I have checked her all over, no pain, no ear issues. The ONLY difference is I gave her Trifexis last night, by the morning she was like this. This is her third month on Trifexis. PLEASE HELP, anything to help me get her through this! I called my vet and they said I could drop her off and they would monitor her, well I can do that here. Thank you for any advice.

      1. Carol says:

        I gave my 1 year old lab her trifexis with a meal and within 2 hours she was disoriented, and stumbling. Rushed her to the emergency animal hospital and they have started Ivs and sedative along with a med to help absorb the toxin. I will never give her trifexis again. SHAME on this company. I pray that Ellie will recover with no lasting side effects.

      2. geroge says:

        gave comfortis tablet to tea cup chiuhaha 3.3 kgs. 6 days later confused skittish, when attemt to pick up screams and screams terrified but of what???? dog never been like this before? just took to vet explained all that has changed is that we used comfortis same active ingrediant as tryfexis which is (spinosad).

        we thought he had back problems cannot be picked up . the vet thought back neck problems. Vet came up with nothing . it doesent take a genious to work out the dog is suffering neurological side effects from this drug. any drug crossing the blood brain barrier has effects. whether inhibiting or promoting. the dog is still spaced out , seems depressed axious and frightened. any attempt to pick him up reults in him completely stressed to the point of terror. very loud screaming.

        dont give any flea treatments to your dog containing (spinosad). we hope our dog gets better dont waste time with vets or safety labels . drugs is buisness just look at proscar for men and neurological side affects . fda approval means nothing . dont give flea treatments to your dog containing spinosad .

    13. Carol says:

      I foster a 1 1/2 yr old Lab Pit Mix. It took me 2 months to figure out what was wrong with him. After his initial dose of trifexis he started vomitting and had diarreha. I didn’t figure it out until the 2nd month. Same reaction and became unstable in moods both times. He will no longer take this product because his behavior and physical reation was no like this on Iverheart.

    14. Carol says:

      I foster a 1 1/2 yr old Lab Pit Mix. It took me 2 months to figure out what was wrong with him. After his initial dose of trifexis he started vomitting and had diarreha. I didn’t figure it out until the 2nd month. Same reaction and became unstable in moods both times. He will no longer take this product because his behavior and physical reation was not like this on Iverheart.

    15. Dave C says:

      Our 1.5 year old scipperki start diarrhea within 3 hours of taking Trivexis, this lasted for 2 days and eventually elevated to hemoragic gastroenteritis neccessitating an overnight trip to pet emergency. $1400 later she is now recovering. We have no proof the medication did this, but she has always been very healthy, has regular vet vesits, and all vaccinations. All tests at emergency found no other cause (ie: parvo, blockage, infection, injury, organ problem, temp, etc) . We will not give her trifexis again, and will not give the remaining pills to any other pets, although not scientific, we know our dog and trully feel her problem came from the trifexis.

    16. Greg Smith says:

      We have a five year old Puggle, five hours after taking Trifexis he stopped breathing, rushed him to ER VET his throat where it enters his chest inflamed so much it cut off all his air. He could not breath, worst thing to have to watch. After over $5,000 in CT scans, test and oxygen he pulled through took about 72 hours. The VET ER docs could find nothing to have caused this, except the possibility of a drug interaction from Trifexis. He can get worms before I will ever put him back on that drug. There are way too many postings of health issues with this drug for the manufacture and or the FDA to do nothing. I am not one to sue but I’m contemplating filing CLASS ACTION LAW SUIT AGAINST Elanco.

    17. Stephanie says:

      Siberian Husky, 4.5 years old
      Vomited 4 hours after Trifexis.

      First dose in February 2013. She wasn’t eating well afterwards, but she was also given an antibiotic and prednisone at the same time and then was on too high a dose of levothyroxine. All of these might have affected her lack of interest in food, so I can’t say it was the Trifexis.

      Second dose in March 2013. Again, given with food. She vomited a LARGE amount (both morning and late afternoon feeding) about 3.5 to 4 hours after ingestion of Trifexis.

      Thank you.

      P.S. I will be starting her back on Frontline or Revolution.

    18. Terry says:

      JaZmine is a 3year old 83lb Weimerana. I started Trifexus about 1 1/2 years ago. Not knowing what the heck was going to happen. I began noticing her upset tummy right after taking the product and then the back legs weakening for about a week or so after dosing. Since then she has had 4 seizures, with the last one finally being directly connected to the timing of her pill. This last seizure scared me for it was over 4 minutes. Since the seizure she’s been to the veterinarian and has been diagnosed with epilepsy. She now is off the Trifexus for the past month and is taking phenobarbital to address the seizures. The coughing, which I thought was allergies has calmed down. Now the question remains, can I ween her off of the phenobarbital since I am 100% convinced the Trifexus was directly linked to the seizures, coughing, weak legs and vomiting. JaZmine is my very first puppy and I would hate to think that I did this by trying to control fleas. She’s my best friend and companion and don’t quite know what to do………….

    19. Derek says:

      Horrible medication. Taking my dog off. Been on it two months, horribe itching, red bumps all over her back. Never had this before this medication. She is a purebred wirefox, 8 years, and no medical issues before this.

    20. Hope M says:

      I’m sorry to hear about all these dogs experiencing side effects =( Our mini schnauzer has been on trifexis since she was old enough to have it, and we’ve never experienced any side effects. She’s 3 now and the only time we stopped dosage is when she was pregnant (she gave birth to 7 healthy mini schnauzer pups!) I guess what works for some, just may not work for others. =/

    21. brenda says:

      my dog rocky had seizures and kidney damage right after a dose of it. my other two dogs were not affected but
      vet was to report it to authorities. I would never use this again, a 45 lb dog part Lab who never had a reaction in his 8 yrs should not have suffered like this.

    22. Kim says:

      For those that have had serious issues with Trifexis…PLEASE file a report with the FDA. You can do this at This is the only way the product can be tracked and taken off the market if necessary! Thanks

    23. Lindy says:

      I almost lost my dog last week. He is a 10 year old Fox Terrier in great shape and until last week, very healthy. He had reactions to Trifexis 2 prior times and my vet told me that it was “rare” ( I have since seen stories after stories like mine so “rare” it is not) that he was vomiting the pills but to try to split the pill over two meals. I practically had to stuff it down his throat last Sunday as he continued to gag it up. I should have known and now feel like I was feeding him poison. By Monday morning, he had thrown up a dozen times and in between he was confused, shaking almost like he was having a seziure and seemed to not remember what his back legs were for. He started foaming at the mouth and was having trouble getting air. This went on for a horrible 6 hours. I called the vet who again told me that they had never heard of a reaction like that. I told him that he should start reading the websites….and he is no longer my vet.
      I am with the others who write here, why do vets give this medication when they know the potential of killing our pets. Mine made it through but still has a shake in his back leg.

    24. Sarah says:

      I gave my 4-year-old golden retriever, LJ, Trifexis two weeks ago. I’ve noticed him scratching and losing hair much more than he used too. I was very hesitant to give this drug to him because it just seemed like a lot of medicine in one pill. Because the topical flea control isn’t working, are there any other options?

    25. Bonnie says:

      I have a 3 yr old rottie and she started taking trifexis about 6 months ago. It has been fine but the last dose I gave her which was Friday has me wondering if it isn’t the issue with the problems she has had the last couple days. She is a little lethargic, no diarrhea but has vomited a couple times a day the last couple days. She seems fine other than the slight lethargy and vomiting but I’m wondering if I continue giving it to her will the symptoms get worse with every dose? I will be consulting with my vet to find out if there is an alternative. I don’t believe I want to give her any more trifexis.

    26. Don says:

      I took my 8 year old female boxer to the vet for a check up. Afterwards our Vet recommended Trifexsis since it was time to administer Heartgaurd Plus, which my dog has been taking with no obvious issues. So we purchased it and gave to our dog that day 23rd of October. The morning of the 24th my dog didn’t want to get up to go out was very lethargic. This is completely the opposite of her. When She did get up she stumbled in to walls fell flat on her face. Once she got her footing we went out. Outside it seemed as If she was patricianly blind and drunk. Having trouble seeing and listening hard for our voice. Inside just sitting around we noticed her drooling from one side she never drools and her face possibly saggy on the same side. No interest in playing. This is very odd for her. She is always full of life. We took her to the Vet today the 28th and our Vet thinks she had a mild stroke. Although she has gotten better in controlling the dizziness it is obvious that she has stroke like symptoms. She is a completely different dog. The only change in her life was the Trifexsis. No diet, Nothing else. I would never give this to any animal again!!!

    27. Keira says:

      I am leaving this as a reply because I cannot find the leave a comment link. I hope everyone can see this. I have a shih tzu that is 10 months old named Khali. First gave her Trifexis last month and the vet gave us the puppy does that is for dogs 10 pounds and under since she is so small. We didn’t have any problems. When I went to the vet this month they moved her up to the 10 to 20 pound dose because she was right at 10 pounds. Since I gave her the dose two weeks ago she has thrown up four times and sometime starts breathing funny. Almost like a child with sniffles from crying. Two quick breaths before a regular breath. I think maybe it is because of the higher dose of Trifexis. I am not going to give it to her next month and see how she reacts.

    28. Steve says:

      after reading more than a few stories about how the dogs (like mine) got disoriented, vomited, seemed out of it. THIS CANT BE A FLUKE! More than several times, reading these comments , it was as if they were telling my story. My dog is a 9 yr old half shih tzu half pekingese about 12 lbs.

    29. Fran says:

      I gave this to my dog and within three months I noticed she was having tremors. I stopped the drug but didn’t make all the symptoms go away. She looses her balance now walks into things and overall health has went down hill she can’t see like she could before and will just start walking around the yard with no aim. She was a healthy 7 yr old boxer but she isn’t any more. I told my vet that I wanted something else for her that trifexis was a nightmare they gave me something else and pretty much didn’t address the issues.

  2. Sandra says:

    I’m not having a problem like I had with Comfortis. My girl is a rescue mixed breed, lab, shepherd,chow, about 60 lbs.

  3. Wanda says:

    My dog has been on Trifexis for a year with no problems at all. She weighs 6 lbs. As said in the article, with any medicine, some side effects can occur. Many of these side effects can occur from taking just heartworm medicine as well. Every animal is different, finding the one that is right for your dog, is what is important.

    1. jessi says:

      I have a 7 lb. bichon frise/shih tzu mix, she is 2 years old and has been taking Trifexis for 1.5 years with no problems other than occasional vomiting of saliva, unsure if it is related.

  4. THRISHA says:

    I have two dogs who switched to Triflexis long before the shortages. One is 5 and the other is 6. They have had absolutely no issues. It has been well over a year at this point.

  5. Stacy says:

    I have a 18 month old male Pomeranian, named Jax. He was on Frontline and Heartgaurd. I changed him over to Trifexis, 8 months ago. Jax has not had any problems while being on it. I have not noticed any side effects what so ever.

  6. Leslie says:

    My two Cavalier King Charles Spaniels have been on trifexis for a year now and have had no problems at all.

  7. Jill says:

    My dog is a 2 year old australian shepherd. I started giving him trifexis about 3 months ago and I have never noticed any kind of reaction on him.

  8. Hannah says:

    I worked at a vet when the product was introduced to me. Both my American bulldog and dachshund are on trifexis. I’ve never had problems at all! I love this product it is absolutely amazing. Follow directions on the box!

    1. vicki says:

      my dog is a 3 1/2 year old aussie – she’s been on triflexis for 4 months with absolutely no change in behavior, appetite, energy level or anything. i did see one flea on her once, however it was very close to her next dosage due date and for all i know it would have died shortly after my spotting it on her. so far so good for us.

  9. Adam D says:

    At the emergency vet right now with the exact symptoms as the scary Internet story. Lethargy… Staring at the ceiling and shivering. Not eating. 2 yr old Australian Cattle Dog

    1. Kat says:

      my female cattle dog had the same symptoms, will never give my dogs that garbage again

  10. Maria S says:

    We gave our 18 month old shorkie his first dose of Trifexis since sentinel was no longer available. Within 5 to 6 hours of taking it our dog vomited and was extremely lethargic and had no appetite. Symptoms continued for approximately 36 hours. We never had any side effects with sentinel.

    1. vicki says:

      put my 3 dogs on trifexis for the first time on Nov,20, next day all 3 dogs no appetite. a few days later my little dashound was vomiting, still no appetite and lethargic. had her at the vets yesterday. and she’s back today, they are giving her fluids and antibiotic’s, something has caused problems with her liver. the vet said it could have been something toxic. after reading about the rumors on the web about trifexis. it has me worried. I don’t think I will use this product again.

  11. Adam A says:

    We have 3 dogs, all turn 7 this month, that we just gave Trifexis to for the second month. The Australian Shepherd and one of the Jack Russell brothers are fine but the one became lethargic and violent shaking. He won’t eat or drink and his pupils are constricted. He is representing neurological symptoms, but the emergency vet told us not to worry unless he is vomiting. It has been 19 hours since we gave him the pill. We will not be using Trifexis again and hope that we can continue to get Sentinal in the future. We have used that for years and never had any problems!

  12. Wendy says:

    We have a 10 month old boxer boy who weighs 65 pounds. I gave him Trifexis for the first time yesterday afternoon, and he seemed fine last night. This morning when he got up, he was very lethargic and droopy and when I fed him, he threw up within about 5 minutes or less. I tried feeding him again later in the day, and he again threw up right away. He is drinking fine, and seems hungry, just can’t keep it down. I took him to the vet and they suspect Trifexis was the cause. Aside from lethargy and vomiting he seems uncomfortable but no other symptoms.

    1. Mojo says:

      My 2 year old Boxer has the same symptoms when I gave him Trifexis. He cannot keep water or food down and just seems out of it for a day or two. Have you found something that works for your dog?

  13. steven says:

    My vet suggested Trifexis, and stupidly, I gave it to my dog without researching it. My dog is a 60 pound pit-lab mix and was almost a year at the time. Within about two hours, she started vomiting nonstop. First we thought it may have just upset her stomach. This went on until the next morning. Of course we took her back to the vet, who said this was most likely a reaction from the Trifexis. Not only was she vomiting, but she was extremely out of it, and wouldn’t eat or drink. She also wouldn’t focus on us or anything around her. This subsided over a few days, however, it took a few days for her to show an interest in food again, and this is a dog who is usually always hungry. Her side effects were mild compared to many that I’ve heard about, but it was scary enough for us. We will never give her Trifexis again after her reaction.

  14. Helene says:

    I have 2 mini poodles and in March accidentally gave both an overdose as my vet filled the Rx incorrectly. My female who weighs 20 lbs. suffered the worst and Elanco confirmed it was 3 times the amount, but she seems to be ok now. My male who weighs 30lbs had no visible side effects, but also overdosed as well. They have each had 2 treatments since and seem okay, but I know long term toxicity and side effects could occur, you never know when. Last night my male appears to have had a seizure, 3.y5 ears old and never had one, the coincidence is too close not to further investigate. My breeder warned me against topical treatments given possible liver damage, why I went with a pill. I’m wondering if anyone else had a similar experience. Elanco claims it should be out of their system from the initial OD, but what if damage was done during and just coming forward?

  15. Andrew says:

    I sometimes wonder if the repeated “my dog vomits” stories are posts from the drug reps of other heart worm/flea medicines. Some of these posts look suspect. Then again, the only people that will find this page are the ones suspecting problems ( or looking to perpetuate the rumor).

    All that said, we have a 6 year old golden retriever rescue who had heart worms ( treated successfully ) and he has allergies. He eats the best primal diets a dog could eat. No grains, no wheat, nothing. I’m beginning to suspect Trifexis. I’ve noticed the last two months that he gets red, itchy bumps on his skin within days of the dosage. His ears start itching him like crazy so much that he tilts his head.

    I think we’ve administered our last dose of Trifexis.

    1. Matt Baker says:

      My 15 week old German Shepherd puppy has experienced the same side effects as your dog as well as other side effects mentioned on this forum after I gave him a dose of Trifexis. I will not be giving him another dose. Good Luck!

    2. Kay L says:

      My 2 year old Golden has developed horrible skin allergies w/ red raised bumps, red skin, and constant scratching in the last 6 months. I am now trying Chinese herbs, homeopathics, probiotics and far he continues to have them. Reading the couple of comments on other dogs, possibly the Trifexis is the cause. It’s administration would coincide w/ these horrible skin allergies.

    3. Jill says:

      Our 7-year-old, 9 lb, very hairy hairless Chinese Crested female had a similar skin reaction. She, too, has a grain-free diet. She had been taking Trifexis for several months, and I am embarrassed to admit it took me that long to notice the cycle of intensity to her symptoms. She started scratching and licking her skin, even digging in to bite at several patches on her back. Our vet did not determine a cause, but gave us a couple meds for any possible infection and for the itching. They had no effect. Once we realized that the intensity of the skin irritation, with incessant licking and biting, was in the days following a dose, we stopped the Trifexis. That was November 2012. It took a couple months for her skin to clear up, but all is well now. Interestingly, our 8-year-old, 14 lb, very hairy hairless Chinese Crested male did not exhibit such symptoms, but we discontinued his use of Trifexis as well.

  16. Elisha Skeen says:

    We have 6 dogs, 4 boxers and 2 Boston terriers. We switched to Trifexis about 3 months ago. Within 8 hours all of our dogs were lethargic and drooling more than usual. Our 10 year old boxer, Bud started having tremors that night, was unable to focus his eyes, and having trouble standing up. This progressed to an actual seizure the next day. He was confused and irritable for days afterward which led to a horrible fight between him and our other male boxer. I realize not every dog will have this reaction to Trifexis, but I think its important for people to know it happened to my dog and could possibly happen to theirs. Bud is fine now, no lingering effects, but back to Heartguard and Advantage for all our dogs!!!

  17. William Bittner says:

    My 9 and a half year old Border Terrier (18 lbs) was switched from Sentinel to Trifexis two months ago. He had no problems with Sentinel. He has had two monthly doeses of Trifexis and exactly twelve days after taking them each month he has had a seizure. He has had no other history of seizures and is active and in good health. I hesitate giving him anymore Tifexis, is their another alternative to Sentinel?

    1. Steve Walls says:

      I have a 105 lb German Shepherd 4.5 years old and, an 80 lb Black Lab 3 years old. We switched to Trifexis 3 months ago. The lab has had no issues, but the German Shepherd had a seizure 3 weeks after taking his second dose. 2 weeks after his third dose he had another seizure. This dog had no history seizures. After discussions with the vet We had blood work done, all results normal. Currently both dogs are off trifexis we are keeping the shepherd under close supervision. We are planning a minimum 90 day waiting period in order to get a reasonable baseline. Further diagnosis will require time, however neither dog will be getting any more Trifexis.

  18. Gary says:

    • Your dog’s breed and age. Rat Terrier Seven years old
    • What side effects are you seeing? Dog passed away
    • How long after giving Trifexis did you see the side effects? Thirty minutes
    Lilly had her rabies vaccination and wellness checkup April 2012.
    Previous meds Iverhart Plus which was what all 3 of our dogs were taking w/o any issues.
    Switched to Trifexis October 2011. Killed fleas in one day off the Yorkie was very impressed with the product. Gave product to all dogs up to June this year. In June had a new refill for Lilly (she is >20lbs the other 2 are<20 lbs.). They all ate their evening meal and then took their meds.
    Thirty minutes later Lilly let out a scream that was almost human sounding jumped up and fell on the floor with her mouth open, tongue out and eyes rolled back. A few minutes later she revived and seemed ok. Contacted after hour ER vet and was advised that if she had not vomited to go ahead and watch her. Same advice from our vet the next day. Everything seemed all right she ate and drank but on the 3rd day she passed out again with the same symptoms as before then revived started to shake and tremble very violently. By the time I got my car keys (less than a minute) to take her to the vet she had fallen over and passed away.
    The other 2 dogs did not show any signs of being ill. All total the 3 had been taking Trifexis for 8 months w/o issues.
    I have no idea if it was caused by Trifexis or what but I did return the product to the vet. I can’t take a chance with the other 2 dogs.

    1. Will says:

      Ilver hart has ivemectin in it. Ivermectin is potentiated by spinosad in trifexis and will kill your dog. Not a theory -says so on box now . Our lab spent 3 days on a ventilator in a coma w ivermectin toxicity after he took trifexis. Same symptoms listed here but far more aggravated. He stopped breathing. Mind you- this was essentially our (vets) fault as it says so on box. 5000 later he is ok. Collies cannot metabolize some components of these meds too.

  19. Robert says:

    have a 2 year old pit bull. gave him trifexis and a day later he is still sick. lethargy, loss of appetite and vomiting. will never use this product again. this stuff is seriously poison.

  20. Hannah Segars says:

    I have a 16 month old boxer. We gave him trifexis for the first time last night. He took it fine, this morning my fiancé got up to go work and noticed he was acting a little drowsy but thought nothing of it. When my fiancé returned from work at 2:30, oleo had pooped (no diarrhea), peed, and threw up in the floor. All of which is not like oleo. When he went to the bedroom he found oleo laying on the bed lethargic and drooling really bad. We took him to the vet and the vet suspects trifexis and gave him zofran for nausea. Since then, oleo has gotten more lethargic, can hardly open his eyes, has an occasional weird jerk motion in his head, can barely stand and is now beginning to randomly cry out or cry out when I touch him along his upper back along his spine. I’m planning on taking him to the vet in am if I don’t rush him down there tonight.

    1. hannah says:

      My 11 week old puppy is having basically the same symptoms. We gave him his first dose on wed, and fri morning woke up to poop all over our bathroom (not like him at all.) He acts hundry but after he eats, he throes up. The only difference I’ve noticed from reading all yhe posts is he seems like hes constipated. I will be calling the vet in the morning and never using trivexis again!!

  21. Barbara says:

    charlie is our 3 year old jack Russell terrier… This is his third month on Trifexis and the symptoms were frightening (loss of coordination, violent shaking, eyes closed and arching head back, smacking gums (nauseous), by the time we got him to the ER vet his heart rate was 220… After evaluating him, they put him on IV to hydrate and acepromazine to calm him so he can sleep through this TRIFEXIS REACTION. Never ever again will I give a dog this drug. It’s more than Internet hype saying its dangerous.. My dog is in the emergency hospital ICU as I type this…

    1. Nancy says:

      What’s the update on you dog?

  22. Teresa says:

    My vet recommended Trifexis yesterday when I took my male pup in to be neutered. Thooght I’d do some research before picking him up this afternoon. Don’t think I am going to go with this product although the vet is pushing it rather hard.

  23. kanmar says:

    My ten year old 25 pound Beagle, Barkley, has been on Trifexis for about ten months. Last month after I gave him his dose he began to exhibit neurological symptoms: lethargy, confusion, weakness in his left hind leg, trembling, and general changes in his normal behavior. He began to go downhill after that point, barely eating, and not leaving his bed. I took him to the vet who tried to come up with many reasons why it couldn’t be Trifexis. She said that if he wasn’t vomiting it had to be something else. She gave him some IV steroids and a course of cortisone pills to do at home. After a couple of days Barkley began feeling better and I thought that the vet was right when she said it wasn’t Trifexis. Two days ago I gave Barkley this month’s dose and he soon began to exhibit the exact symptoms as last month, only more severe. I’m taking him to the vet this afternoon, and will be a little more forceful about Trifexis as the cause of his symptoms.

  24. Jean Ayers says:

    I just want to thank everyone for taking the time to write in their feedback on Trifexis….I just returned from the vet with
    Trifexis in hand for my Great Pyrenees. He has flea allergy and
    one flea bite creates much hair loss and intense biting and scratching. I’ve used Revolution without good results so the vet
    recommended Trifexis…
    After reading all the feedback I’ve decided I will not be taking
    any chances with my dog….not sure what I will be doing but I am certain I won’t be using Trifexis….

    Many thanks to all who shared their experiences….

  25. Susan says:

    Gave trifexis to my mother’s small sheltie/pomeranian mix (4-5 years old) when he was visiting with us about 10 days ago. His weight (21 lbs) pushed him over to the next higher dosage and I was a bit concerned as he has sometimes gotten sick if he has interceptor and frontline on the same day. He seemed okay at first and then had a loss of appetite; still drinking water and otherwise acted fine. No vomiting until about four days later when he began eating sporadically. He still is not back to his regular feeding schedule (twice a day) but is now eating in the morning and still drinking water. He has vomited a couple of times during the night since he has gone back to eating regularly (bile, since there is no food in his stomach). I contacted our vet who recommended chicken and rice until his stomach settles down. We obviously won’t be giving him trifexis again, nor will I be giving it to my own dogs. I have also contacted Elanco Animal Health as outlined on the trifexis site ( to report the adverse reaction.

  26. Kayleigh says:

    I gave by 8 year old boxer/pit mix his first dose of Trifexis yesterday. Today he’s been very lethargic (so much so that he does not want to go outside), nauseous, and occasionally winces as though he’s in pain. He’s still eating and has not vomited, so I’m hoping his discomfort will pass with some rest. If it gets worse we’ll be heading to the vet. I was reluctant to try Trifexis in the first place and I doubt we’ll be giving it another shot.

  27. Ellen OBrien says:

    We adopted a Pembroke Corgi from a shelter. As part of his initial exam by our vet, he was prescribed Trifexis. Since he had already been dosed in the shelter, we waited a month to administer the trifexis. He vomitted the first dose so was given the second dose as per patient instructions. This morning hewas lethatrgic so I called the company to report the side effects. They were quite ready to imediately refund my money. Called the Vet Clinic to explain what had happened. As the day is progressing my corgi is getting increasingly more lethargic, breathing hard/panting and fairly unresponsive. We will NOT be giving Trifexis to any of the other pets in my home. It is “wait and see” whether we take the corgi to the vet this afternoon just to make sure this is a “normal adverse reaction” or the side effect is as serious as it looks.

    1. Jarrad says:

      Sorry to hear about your corgi. We have been giving our corgi Trifexis for the last 5 months. We were a little skeptical after doing our research and seeing the horror stories but we monitored him heavily after the first dose and have seen zero side effects.

      It has worked so well in fact that we didn’t feel the need to use Frontline anymore. Before, we had him on the Sentinel/Frontline combo.

  28. Kim W. says:

    Gave my quite healthy 14 yr. old female lab mix her first dose of Trifexis about a week ago. She’s been a little droopy since, but it’s been very hot here too. Then this evening when we went for our usual sunset walk, about 10 minutes into it, she wasn’t able to continue, she laid down and wouldn’t get up. I had to carry her home. Her gums were very pale, I thought I was losing her. After an hour or so of resting she seems to be recovering, her gum color is much better, and she has gotten up and walked around a little; but still isn’t quite right. Trifexis to blame?? Don’t know, but if she survives, don’t think I’ll try this stuff again; especially after reading about all these other adverse reactions. (This dog has never had a reaction to HW / Flea preventive before.)

    1. DrMarie says:

      I’m sorry to hear about your dog. In this case, I am guessing that the side effects are not related to Trifexis. You may want to have your vet take a look at your dog. The symptoms sound similar to either a bleeding spleen tumor or a serious heart issue. Hopefully she can be seen soon, and hopefully she is ok!

  29. wendylynn says:

    I took my four yr old collie for her yearly checkup last week. My vet is also out of the interceptor (I dont give products with ivermectin to my dog). My vet suggested I switch to Trifexis and I could forgo the “oil” ( K9 Adavantix 2) that I use topically for flea/pest control. My dog threw up several times starting about a half hour after giving her the pill. I gave her food with it, just like my vet told me too. She was also lethargic and didnt want to eat anything until the next day. I will not give my dog Trifexis anymore. I am returning the remainder of the prescription I have. I will cont to use the Advantix 2 and use the remainder of the interceptor pills I have left, next month.

    1. DrMarie says:

      Don’t be too afraid of using Ivermectin. Here’s an article I wrote about some of the misconceptions out there in regards to Ivermectin: Is Heartgard safe for collies?

      1. Gary says:

        Misconception? I don’t know about that. Washington State University, which spearheaded the MDR1 study publicly stated in the beginning that any dose of Heartgard was harmful to the herding breeds with a 75% occurrence in Collie’s. they have since revised their conclusions. I strongly suspect this change of heart on their part was due to pressure from the companies that use Ivermectin as an active ingredient. Money comes first and unfortunately our dogs come second. I have seven Australian Shepherds. Years ago, when I got my first Aussie, I hadn’t ever heard of the MDR1 mutation and apparently never had my Vet at the time. He slipped my Aussie puppy a Heartgard cube before I even realized what had happened. That night I thought my dog was going crazy. He began pacing, drooling, and snapping at the air as well as vomiting and diarrhea. It only lasted that one night but that was enough for me to realize that this wasn’t something he should be getting on a regular basis. I fired that Vet and found one that knew something about MDR1. It will amaze you how many don’t know anything about it. My new Vet switched my dog to Interceptor and I’ve never experienced any side effects since. All my subsequent Aussie’s have been on Interceptor since they were old enough and I’ve never had any side effects with any of them either. I am a strong believer that any dose of Ivermectin is harmful to a MDR1 positive dog and I speak from experience.

        1. DrMarie says:

          Do you have a link to this statement from the University? Thanks.

  30. Daniel says:

    Gave my lab/collie trifexis according to the directions and he was a little lethargic the first night. The next morning, he didn’t want to get out of bed. I finally got him up and walking around and good enough to eat breakfast, but he is still very lethargic.
    My vet is excellent but this is a let down. I had thought they would have researched this (like I should have) before selling.
    Anything that makes your dog feel this bad is not good for them.

    1. Gary says:

      I think a lot of their “research” is conducted with the unsuspecting public.

  31. Shirley says:

    My 7 month old very happy, active and healthy lab/pyrenese mix has been at the emergency vet clinic since yesterday morning. I gave her Trifexis at 8 pm the night before. She was fine when we went to bed. However yesterday morning she was unresponsive and comatose, I took her to my regualr vet who stated she she go the local emergency clinic so lab work could be done immediately. She remained comatose for 24 hours. The emergency vet contacted the Trifexis manufacturer and was told that comas are a known side effect of Trifexis as the main igredients retain a subtance called GABA in the brain which induces unconsiousness, The trifexis rep also stated that most times this sde effect lasts 48 hours and that oftentimes the dogs have a full recovery without organ or brain damage. The emergency vet administered 2 lipid IVs to bind the active ingreditents of the medication as they are fat soluble. As of today my dog has shown some inprovement but is not of out the woods yet. Her eyes are different and she has some neurological impairments. I am out thousands of dollars for this emergency treatment and I am a retiree on a fixed income. In addition I am heartbroken over seeing my dog suffer. Does anyone know an attorney who might consider a class action lawsuit. This has been a heartbreaking experience and I still do not know what degree of recovery my dog will have.

    1. shirley says:

      the vet at the local emergency vet clinic stated that collies and shelties have a gene mutation that causes severe reactions for these breeds when given Trifexis.

      1. DrMarie says:

        I think there may be some confusion there. Many collies and shelties have what is called an MDR1 gene defect that makes them more sensitive to ivermectin and milbemycin than other breeds of dogs. Even though there is milbemycin in Trifexis it is in extremely small levels that are definitely safe for collies. You can read more about this here: Are Heartworm Medicines Safe for Collies?

        The main concern with Trifexis is the other ingredient, Spinosad. There is no evidence I have seen so far to show that Collies are more sensitive to Spinosad than other breeds.

    2. Matt Baker says:

      If you find an attorney to work towards a class action, let me know because I would be willing to participate. Email: I’m so sorry that your baby had to suffer.

      1. Adrian says:

        This is very scary. My frenchie, Claude, experienced same shaking, straring at ceiling, lethargic symptoms last night. He had done this before and after $600 of tests at the emergency vet, the vet found nothing. I asked if it could be due to the Trifexis, but he said no. Claude normally takes Sentinel but since it was on backorder the vet prescribed Trifexis as replacement. It all makes sense now after reading everyone’s experience. Thank you to everyone for sharing your details. Say NO to Trifexis! I’ll be calling the manufacturer today.

        1. Brooke says:

          I had a 5 year old bull mastiff /pit bull mix. He was perfectly a happy healthy dog. The sunshine of my life. I had given him two doses of trifexis. I had to put him to sleep after he suffered 3 major seizures in an 8 hour span….. This happened out of the blue, no previous seizures or signs of epilepsy m… Vet did an “autopsy” of sorts and she found a mass in his belly and pretty much said it probably metastasized to his brain causing a brain tumor….. Here I am now 2 months later, devastated, holding my head in my hands as I read these posts….. I poisoned my best friend in the world with trifexis . Please let me know about a lawsuit. It’s not about the $$$ for me. They won’t stop making and administering this drug until something happens….
          RIP Hando ~I am so sorry.

      2. Karla Jones says:

        I would also be willing to participate in a class action suit.

  32. Elizabeth says:

    WOW! I am almost afraid to give my Australian/Jack Russell Breed (I know weird breed but such a great dog) the trifexis again. She has been on it for a year now I have not seen a problem at all. I give it to her crushed up inside a can of pedigree wet dog food. She weights 64lb & loves to swim in the river. It was a great thing to give her considering she always was jumpin in the water so the topicals (frontline, advantage) never worked.I have even noticed that if a tick bites her it will instantly dry the tick up & it dies?! She was tested for heartworms & a full exam before she was given the trifextis. I am soooo sorry & my heart aches for the people who has lost a member of their family from the result of this pill. But my dog as done really well with it BUT the first sign of a side effect I will stop giving it to her! After her bein on it for a year so im goin to keep giving it to her :-/ but the first sign & she will be getting something else for protection. <3

  33. Jeannette says:

    I have been giving TriFexis for a couple of months now. I have 3 kids, 12 year old Airedale Lab mix with cancer 95 pounds, 4 year old Airedale 65 pounds, Cane Corso Mastiff/Lab mix 18 Months old, 90 pounds. I know right, he outwieghts the Airedale. The older pup doesn’t have an issue eating that huge tablet. The other don’t do so well with pills. I managed to get it down by breaking it up and giving it in pieces, wrapped in cream cheese. Last couple of months they got the single dose over two days. This week, it was one tablet all in one day. Well the puppy has been yacking up meals and has really bad diarrhea. I gave it with a meal, but he is having issues. Fed him only brown rice in chicken stock and Pepto and he seems to be coming along. Also gave him Lactobacillis Acidopholis for tummy.

  34. Pablo says:

    Dont give your dog Trifexis. Yes, there is a lot being said online about it..i didn’t know about any of it until i saw side effects in Frank and i googled it. He hasn’t been eating well since he took the pill; he would never leve a kibble and now doesnt care when i pur him his bowl. This morning I woke up to him with poop everywhere in his crate (poor guy couldn’t hold it through the night) he was covered in a mix of diarrhea and drool, his skin is all red and hes got a sore on his nose. He looked terrified. Hes OK, not lethargic or acting weird or anything, the pill is just messing him up. So…just dont give Trifexis to your dog. Dont risk it. Wait for frontline to come off backorder.

  35. Mary Sangrey says:

    I have two four year old, healthy, fit Siberian Huskies. Like most this year, we were’t able to get our usual heartworm medication so our vet recommended that we try trifexis. The first month we noticed that several hours after giving them the pill both were lethargic, certainly not acting normal. The one in particular seemed particularly out of it – drugged – but after about 24 hours both seemed find. The next month was a different story. We gave the meds in the morning. Upon returning home from work in the evening both were not normal but the one who reacted more the first time was clearly not well. He was beyond lethargic, struggled to keep his head up and was not responsive. Normally upon returning home in the evening we go for an evening run and both are bouncy energetic normal huskies anxiously waiting to be leashed. However this evening neither hardly reacted, and the one didn’t even move or lift his head. We called our vet and after some discussion and trying a couple things we ended up at the emergency vet, where we spend most of the rest of the night. A battery of tests and x rays, and such, yet nothing was conclusive We ruled out any possible poisoning and other hazards or injury. After about 24 -48 hours he was well. The only link is the trifexis. It may be that for some reason he is more sensitive to this particular drug than others. However, I have great concerns based on the reaction of both my dogs, and the one in particular. I hope my vet submits the results to the company for reference, even if an isolated case, these should be documented.

  36. Lisa says:

    My 5 mo German Rott had her first dose of Trifexis on Thursday, by they next morning she was vomiting, lethargic, refused food and water. We ended up at the ER vet by Sunday morning around 12:30 am with continued vomiting and bloody, mucus diarrhea. She had to be carried as she was too weak to walk. She was dispondant, and noticeably uncomfortable. The vet wanted $900 up front to begin a treatment plan. We did get something for nausea and vomiting with gave me a few hours to get Lola rehydrate… or try! I literally had to sit over her with bowl held to her mouth to get her to drink. She has still not eaten anything in almost 72 hrs now. We made it to our regular vet this am, Lola went from a beautiful 41 lb healthy girl to a weak, frail, 32 lbs and has lost all glow in her eyes. She looks so far away now that I wander if we can get her back! I am so angry that my dog was poisoned by the same hand that treats her. I know not every dog has the same adverse reaction to this medication, but obviously enough of our fur babies have suffered to realize there is a problem with this medication. I want my Lola back! I want my bouncy baby girl, who loved to run around and play and eat! I am just so sad seeing her so sick! We as animal owners trust the responsibility of caring for our dogs with our vets…. seems like until the vets take a stand and say this has to stop… other dogs are going to die due to this medication.

    1. joanne says:

      Lisa, that is so sad. I hope you have your baby back by now.

    2. Nancy says:

      Omg , how’s you poor puppy, ours is going in this morning , same symptoms!

  37. Laura says:

    We gave our 14 year old chocolate lab Trifexis for the first time last weekend after Sentinel became unavailable. We gave the pill with food that morning and by mid-afternoon, he was completely lethargic–would not lift his head, his eyes were rolled back and couldn’t focus and he was trembling. We physically got him up and he just stumbled around. We dropper-fed him some water and we started to see some improvement by late that night. The next morning, thankfully, he was back to his normal self. Needless to say, we will NEVER give him this medicine again and feel so bad we did that to him!

  38. Jody says:

    I gave trifexis for the first time to my 8 year old 11# pomeranian. She was fine for the first 36 hrs and then she started acting strange. She wouldn’t lay down, she just hid under the bed and wouldn’t come out to eat or go to the bathroom. When I did get her out it seemed like she couldn’t stand up very well and seemed to be shaking a bit. She also cried out when I petted her head. Very lethargic,but she never vomited (at least not that I know of) she will eat and drink water and she will go outside to pee and poo. But she is definately not the same dog. I’m wondering how long this will last? I’m not going to be giving her trifexis again or either one of my other poms. Where is the sentinel at?

  39. Milagros says:

    Hello, I witnessed the most horrific episode of convulsion/seizure on my Labrador Peggy. We started her on Trifexis about 2 weeks ago, the first day she was a little lethargic but the next day she was ok. But yesterday my dog was twitching, panting, twisting out control and felt on the floor as she has been stroke by lightning convulsioning as an epilepty would do. I have to say that she has been a healthy dog, no health problems at all and the only new thing on her diet is this medication, I took her to the vet today and she said not to give her the Trifexis anymore. She said that this medication can trigger epilepsy and can produce epilepsy in some dogs. However, she also said that it wasn’t enough evidence to support that, but not to give it to her anymore. Also, I need to say that I have a poodle that took the same medication as Peggy and she seems to be ok; however I was so scared yesterday that I am not giving this product to any of my dogs anymore. I don’t think is safe, the company should put seizure as part of the possible side effects….

  40. AmyJ says:

    My 5 year old mix (goldendoodle 90lbs) experienced vomiting the day after taking the Trifexis. He can take Comfortis and Interceptor, individually without any side effects. His appetite was also very low for a week after the Trifexis. It costs more but I buy the two pills and give them a few days apart. He does fine like that.

  41. Jessica says:

    My dog is an 18 month old Queensland Heeler mix. He has had really itchy skin, chronically itchy to the point where he itches so much he bleeds. I forgot to give him two doses of Trifexis, and he was seemingly better. I gave him Trifexis again, and his itching started up immediately. I’m not 100% that Trifexis is causing this reaction but I’m thinking of switching to a different medication to see for sure.

  42. Laurie says:

    I gave my 11 yr. old Lab Trifexis the first time on June 1. A couple of weeks later she developed a ‘mole’ on her snout. The 2nd dose was July 1. After looking at this mole for a few weeks I decided the Vet needed to see it. They did a biopsy and determined it was a mast cell tumor. We are now seeing an Onocolgist and getting treatment.

    She had been on Hartguard and Sentinel for years. Could there have been something in the Trifexis that triggered this? Have you heard of any other instances of something like this? I’m just trying to find out if there might be a possible connection.

    1. DrMarie says:

      Most likely this mast cell tumor is totally unrelated to Trifexis. I really can’t see how there could be a connection. Hope things work out ok for you!

  43. Tiffany says:

    I recently got back from my vet’s office because I went to question about Sentinel and why it was no longer being sold and I asked for what I should give my dog now and the vet tech suggested Trifexis. After reading all these reviews I am deciding to not even TRY my dog on this product. She is recently on Comfortis & Sentinel and hasn’t had any problems. (She’s a 50 lb. Lab/Boxer mix.) But now I only have one Sentinel pill left so I need something soon. I may just use Heartguard. I really am sorry to everyone on here who has had problems with this medication and I hope everyone’s dogs are doing okay!

  44. Debbie says:

    My 11 1/2 yr old Border Collie mix just had labs prior to some dental work. Her liver enzyme ALT has increased by more than 3x since being checked in March 2012 (due to being on Rimadyl for about a year). It is now way over normal. The only change is that three months ago – April 2012 – I started my dog on Trifexis. Has anyone heard of it affecting liver function? I have not noticed the specific issues noted here by many – but have been searching tonight for information about impact of this medicine on the liver.

    1. DrMarie says:

      I am guessing that this is unrelated to Trifexis but thank you for sharing.

    2. vicki says:

      my dog started trifexis on the 20th of nov. became sick the next day. would’nt eat. vomiting. took her to the vet. she has been having IV treatments for the last 2 days for liver. Rsearched trifexis on line . and found out of other people having problems with their dogs, same side effects. contacted Alanco animal health. I will never use this on my dogs again.

    3. Leslie says:

      That seems odd. Giving your pet comfortis and Sentinel combined is the same as giving Trifexis?

  45. jason says:

    Trifexis is terrible

  46. Becky K says:

    I have a 8 year old chocolate lab and 9 year old jack russell terrier, both in good health. Both have used Interceptor and Frontline (as needed) for years with no problems. I went to get their 6 month refills last month and the vet convinced me to try Trifexis. I did not research Trifexis, trusting my vet’s advice. Upon giving the dogs’ their first doses, I watched them to see if there was any stomach upset (which sometimes happens with a new medication). Everything seemed fine.

    About 24-72 hours later, both dogs had vomiting episodes. The jack russell vomited bile (bright yellow) 4 times over the course of one weekend. The lab vomited only once that I am aware of and it had the color and consistency of water. For the remaining 3-4 weeks, both dogs have had the gag reflex several times, but no more vomiting. The lab also urinated in her sleep one night. She sleeps on a pet bed in our laundry room which has dog door access the back yard. She has never done this before. There have been no other unusual behaviors. Appetites and energy levels have been fine.

    It is now time to give the dogs’ their 2nd doses and something told me to read up on Trifexis. This is the first website I went to. I can’t believe what I have been reading. I have absolutely no idea if my dogs’ unusual symptoms this month have anything to do with Trifexis, especially since they did not begin until 2 days after dosing. However, I think I’ll change back to the meds that worked before.

  47. lauri fleming says:

    I have a female 4 yr old boxer/pit. She has always been o Sentinel. On Jun 21.2012 I gave her Trifexis as per vet’s recommendation due to unavailability of Sentinel. The follwing day she had yellow runny stool. This continued for a couple of days so I added some pumpkin but saw no change. I then started her on chicken and rice and that has firmed up her stool somewhat but still yellow. She acts totally fine other then this. On July 21, 2012 I gave her Sentinel and was hoping things would clear up. Still no change and she has lost almost 10 lbs. Went to vet’s today and they did fecal test which was negative and a giardia test also negative. The vet has prescribed Metronidazole and also Panacur and said to keep her diet the same for the next 5 days and then slowly start the tranistion to regular diet. My 2 yr old male Pit was given Trifexis the same day and has had no ill effects. If this treatment for my female is ineffective then more testing will be done. I will never ever use Trifexis again. My close friend who has been a registered vet tech for 30 years said they do not ever recommend Trifexis for their patient

  48. Judy says:

    My 10-year-old miniature poodle has been on Interceptor for 8 years without ANY adverse side affects. He weighs 27 pounds. Today, I gave him his first dose of Trifexis along with his meal. I made sure he had food in his stomach before giving him the Trifexis. He threw up twenty minutes later and has been lethargic for the last 4 hours. I will be calling the vet in the morning. I hope he will be okay. I will never give him Trifexis again.

  49. Kristyn anderson says:

    I have a 16 wk catahoula lab mix puppy. First dog ive owned in 10 years. I have only had her for 4 days and took her to the vet today for the first time to treat tapeworms. While there I picked up some brochures and one was for trifexis and the other for a topical multi preventive treatment. I began to do research on trifexis first because I love the idea of a chewable instead of topical. When to petmeds to check price and read user reviews and they honestly scared me. I’m sorry but I just can’t take that risk. It may end up being fine and a great med but if I were to give my baby something knowing it may hurt her and it does I will feel horrible. Is there a good multi preventive chewable out there without all these crazy stories attached to it?

  50. Carl says:

    We have a 4 month old mixed breed puppy. Took her in for booster vaccinations, rabies yesterday and the Vet gave us a single dose of this Trifexis to give her when her due date arrives on the 10th. We like and trust our Vet and her judgment. There are no guarantees in life for humans or our fur babies. Like someone else said in a previous comment, who knows if drug reps are putting out false reports or not, it is a cut throat business. I have had adverse reactions to prescriptions given to me by my Doctor, it happens.

    I think it is also very important to remember, there is a REASON why these folks spend YEARS in Vet School and then pass BOARD EXAMS to get a license to practice Vet medicine, THEY KNOW WHAT THEY ARE DOING and no, we are not their peers because we learned how to use GOOGLE and think we are bright enough to understand and believe gossip on the internet!

    1. Linda Foster says:

      I agree with what you are saying about the Vet. They obviously should know what they are doing in that field of work and I don’t blame the Vet for what is happening with this medicine. I just don’t think enough study was done on it before the manufacturers made it available for people to use on their pets.
      But, I also don’t think that the comments these people are leaving on this site are just “gossip on the internet”. I have experienced some of these same horrible side effects with my 3 yr. old Maltipoo who just had her checkup/bloodwork and everything and my Vet said she was perfectly healthy. So I know for a fact that 4 days ago when we gave her the 2nd dose of Trifexis, all these things that are now happening to her are because of this medicine. She runs around chasing her tail and biting at her paws, panting feverishly one minute and the next minute she is staring out into space in a daze. She is vomiting and has diarrhea at the same time. She is like a rag doll because of the lethargy even though 4 days ago (before Trifexis) she was a perfectly normal energetic little dog. Dr. Marie is doing a good thing in allowing people with similar experiences to talk about it here. This is not gossip, this is truth and people who are truly concerned about the welfare of their pets who are like family.

    2. Rosemary says:

      A patient must advocate for themselves but a dog can’t speak therefore as owners we must do this for them. No reason to believe why so many pet owners would post negative side effects if it wasn’t TRUE.

  51. Sweetpea says:

    We have two female dogs – a collie mix, 8 years old, and a Belgian Shepherd mix, age 3 years. Both gals were on Interceptor with no problems. We never gave them flea medications in the past because in the area where we live, fleas are not an issue – but heart worm & parasites are. When the plant closed down that produced Interceptor, we discussed the issue with our vet and chose Trifexis as an alternative, even though the flea prevention part of it was unnecessary.

    This was three months ago. My collie girl has had no problems whatsoever. But woe is me…I see now that our shepherd’s intense itching problem can only be caused by the Trifexis. After giving her the tablet last night, the signs were unmistakable. She went into a rage of non-stop scratching, starting first with rubbing her snout back & forth vigorously on the lawn right after eating (and ingesting the tablet) and then spent the entire night biting at herself, scratching endlessly, until finally at 6:30 a.m. my husband gave her a Benedryl to alleviate her discomfort.

    Some backstory on the itching: two months ago, we had taken her to the vet for her annual checkup. We reported that she’d been having quite a lot of itching problems, even causing bald spots in some areas and little red, raised bumps on her belly & we couldn’t figure out what was causing them. The subject of the Trifexis came up (she had received her first dose the month before), but our vet was skeptical about placing blame there and thought perhaps it was more likely “seasonal allergies.” We do live in a rural area surrounded by a lot of pollen from grasses & trees so this seemed quite possible. But just in case, I took other measures as well. Although we fed a grain-free, high quality kibble, I switched both the dogs to a raw food diet in case something in the kibble was bothering our Quinnie. I vacuumed the house thoroughly & kept their bedding clean & washed (to combat household allergens). I gave her fish oil-based supplements known to help allergic skin problems, and also bee pollen. And although it was slooooooow to change, her itching had noticeably started to calm down in the last ten days or so.

    Until giving her the Trifexis tablet last night. We are back to square one and our poor gal is beside herself with scratching. She also is biting at her forelegs, her flanks, and chewing on the pads of her feet. I am heartsick to have sent her back into this state. One thing is certain ~ she will never receive another Trifexis dose EVER.

    Thank you so much for the opportunity to share our experience here. I hope it helps others.

  52. Robin says:

    I Have used trifexis for all of my pets-3 dogs. One a border collie, another a small mixed breed 20 lb dog, the other a lab/coonhound (75lbs). I love the stuff!

    It works well, I have never seen any side effects, and I have used the product since it first came out on the market.

    I had used comfortis at first, until trifexis came out. As far as reports go of issues with the meds-I just think it has to do with the animals not handling that particular med as well as another. IE: some people can eat melons fine, others have a reaction to melons (itchy mouth) or penicillin allergies, etc. The heartworm medication is not always tolerated by some dogs…that has always been the case.

  53. Emily Johnson says:

    Hi. my dog is currently sick most likely due to Trifexis.
    My dog is a 5-6 lb female 2 yr old chihuahua mix. Here are the facts…

    1. She’s had it twice before with normal lethargy and vomiting side effects
    2. I gave this dose with chicken and low fat cheese
    3. She began vomiting within 1 hour
    4. 24 hours later her vomiting and diarrhea had not diminished
    5. Took her to emergency vet clinic. They said probably not the Trifexis. I disagree. She’s an apartment pup and had been given nothing else. Big coincidence if vet is correct.
    6. Vet gave her fluids and anti-nauseau
    7. 36 hours after administration of Trifexis she still won’t eat and is doing weird things like chewing on the carpet.
    8. Her blood work came back normal

    I just don’t believe these symptoms aren’t Trifexis caused. It should be noted that our 20 pound terrier did fine with his dose. He was pretty lethargic, but no vomiting or diarrhea. Based on this and people’s comments, I think the key is weight. Perhaps Trifexis is too much for little dogs. Either way, Dottie is going back to Heartguard and the oral topical flea treatment we’ve always used. She never had ANY symptoms with those.

    Best of luck all. Hope my situation prevents other pups from being sick.

    1. Annette says:

      My yorkiepoo experienced at least one seizure after taking Trifexis. My vet’s office said it was a coincidence. However after calling Elanco, the company that produces Trifexis, they told me that these adverse reactions sometimes occur. My pup is 6 years old and has never been sick, never experienced a seizure. I am unsure what he had to endure for the 9 hours I was at work after ingesting this poison. Call the company at 1 (888) 545-5973. Report all adverse reactions. Make this company aware that we as consumers will not tolerate this careless behavior on their part.

  54. Teresa says:

    My 16-year-old toy poodle had no problems all these years on Sentinel. First dose of Trifexis resulted in loss of appetite and diarrhea that is still going on after 2 days. Now she is on Metronidazole and chicken broth/rice/boiled chicken. I hope this gets better soon.

  55. carol says:

    Our 2.5 year old dachshund started taking Trifexis about a year ago. After the first dose he was very lethargic. We reported this to the vet who felt sure the two were not related but said to watch him and let her know if it happened after his next dose, which it didn’t. After about 6 months on the trifexis he had a seizure. We rushed him to the vet who was not convinced it was a seizure but there was no doubt in our minds. No mention was made of the trifexis. Instead she said he was dehydrated and had a touch of pancreatitis. ??? And that perhaps he was trembling due to pain. Just by chance we were out of Trifexis for a few months and he has just started back and has had three doses over three months, during which time he has had two more seizures. It seems awfully coincidental but none of his seizures were right after the medicine. The closest one was 8-10 days after a dose. In any case, I am taking him off the Trifexis after reading all these comments and am hoping this will stop the seizures. Do you think I can ask the vet for a refund of what is left of the medication?

    1. Kim says:

      This is enough for me. I tell you I won’t use the stuff again. Why is this stuff even allowed on the market?????

  56. Barb Kube says:

    I have to disagree with Dr. Marie and I hope she will consider revising her belief. Here is the statement for which I disagree. “Many collies and shelties have what is called an MDR1 gene defect that makes them more sensitive to ivermectin and milbemycin than other breeds of dogs. Even though there is milbemycin in Trifexis it is in extremely small levels that are definitely safe for collies.” The safe part is simply NOT true. Our Border collie/Aussie mix just had a horrible seizure, lasting well over an hour, two days after giving her Trifexis. She had 2 smaller seizures before and we now put it together that is was one or two days after giving her Trifexis. I think it is like poison ivy in humans Some people have to be in direct contact with the plant to develop symptoms, yet others can just be in the area. Some dogs with the MDR1 gene may not be affected by the small dose in Trifexis, yet others most deffently are! We just got back from the emergency room, and the vet there said she DOES think there is a link between the two and said she doesn’t prescribe Trifexis to any herding dog unless she knows that they do not have the gene. All herding dogs do not have this gene, which is why some owners report having no problems with the medicine. I think this is sound advice. If you have a herding dog (or shepherd) do not give this to them unless you know it hasn’t caused problems in the past. As far as the stomach troubles, we have not had these problems, but if your dog did, please discontinue use. This medicine contains an insecticide.

    1. DrMarie says:

      Hi Barb. There is a warning on Trifexis that says it should not be used in dogs that are prone to seizures. I’m not sure that this is connected to the MDR1 gene however. I’m not sure if you’ve seen my article about heartworm prevention and collies, but it is all about dosing. The FDA has stated that all of the currently available Heartworm medicines contain doses of either ivermectin or milbemycin that are considered very safe even for dogs with the MDR1 gene.

  57. Rae says:

    I have a 1.5yr old Great Dane who has been on Trifexis for about 3 months now. Previously he was on Heartguard (which had to be double dosed because of his weight). I work at a local animal hospital and the Trifexis product is new and exclusive to our clinic in the recent months. I have had no complaints regarding Trifexis. We advise all of our clients to administer the tablet with a full meal and inform them of the small possibility of vomiting. If the pet vomits within one hour of consumption, you do need to give another full dose of Trifexis. However, if an hour has passed, then you do not need to worry. This medicine is, as noted, not advised for pets with a history of seizures. This medicine should also only be sold to a dog that has been tested NEGATIVE for Heartworms.

  58. Laurie says:

    4 yr. old Irish – on med. 4 mnths. Within 12 hours – diarrhea, loss of appetite, lethergy. Going on a search for an alternative.

  59. Lorraine says:

    My dog Annie has been on Trifexis for 2 months now. The first month, she vomited and had diarrhea afterwards, but it was also at the same time as a change in her diet, so we figured that was the culprit. This month, all was well until she took Trifexis. She had explosive (and I mean explosive) diarrhea for 3 days… she’s now slowly getting back to normal. Looks like it’ll be Heartgard and Advantage for her from now on…

  60. Jeanne Stephens says:

    I have five shelties on trifexis. Been on it for three months. No problems. My shelties are in good health. Maube that is why there have been no side effects.

  61. Kim says:

    Hello Dr.,

    I gave my three dogs a dose of Trifexis yesterday and have seen no effects yet. When I went to my vet they were out of Sentinal and recommended the Trifexus. Now that I’ve Googled it, I will NOT give it to my dogs again. Period.

    I know that heartworm is a threat but a pill that surges through a dog’s system and out its skin to kill fleas cannot possible be anything but bad. It’s poison plain and simple. I’m personally fed up with having this sort of guilt trip being foisted on me by my vet who advises that I bombard my poor dogs with everything coming and going – no offense doctor, I’m not impugning you or my vet or any vet.

    But dog owners are guilted into this sort of thing and I’m tired of it. it’s as if not dosing dogs with these dangerous chemicals makes one a bad dog owner. My last dog lived to be well over 13 and he never was sick a day in his life and never had a Sentinal or anything like it. The dogs I have now always seem to have problems – either skin problems or digestive problems or stomach problems. One has colitis as well.

    What are dog owners supposed to do?????? And how could any researcher possible know what sort of effect these treatments are having on a dog’s sense of well being if they aren’t showing outward symptoms? Maybe they have headaches or body aches or disorientation similar to what humans experience from allergy medicines.

    If I knew what I know now, I would not have given Trifexis to my dogs whether they show symptoms or not! This is downright irresponsible!

    1. Rosemary says:

      Well Said!, my thoughts on comfortis was the same the first time I gave to my pit/lab mix for the first time last year along with interceptor but thought it was ok since I could give only when I thought the comfortis was needed for fleas. Now that interceptor is not available & giving trifexis the combo, I don’t like the combination which I think is the problem. This is the 6th or 8th month for Trifexis & my dog is experiencing extreme colitis type diarrhea this Saturday morning after taking her monthly dose last night. I WILL BE CALLING MY VET Monday morning & also Elanco the makers of Trifexis. My son’s dog has just experienced the same symptoms

  62. Shannon says:

    I have a 3year old lab mix (110lbs) and a 18 month old lab (65lbs). Both have been on Trifexis for 12 months at least. Neither dog has had a single side effect, nor have they had any worms or fleas since being on it. Both dogs are up to date on all vaccinations and are routinely seen for check ups.

    1. Jeanne says:

      My 15 month old Havanese weighs 8 lbs and has been successfully taking Trifexis for 11 months now. She has never had an issue with it; NO vomiting, trembling, or any other kind of reaction. I believe the info people are reading on the Internet of it being unsafe is wrong and definitely not based on accurate data.

  63. Phil says:

    I have an 9 mo old Shiba inu. 25 lbs. only issue with trifexis is the loss of appatite and laziness for about 2 days afterwards. 4mo into it and this symptom seems to be going away. maybe a tollerance build up. the stuff does work however.

  64. Carol says:

    I have a blind mixed breed beagle, 10 years old , 38 pounds. Gave her Trifexis yesterday morning with her breakfast. This was the first time on this medication since we could not get Interceptor. She was fine all day today but tonight she had diarrhea. I hope this is the only side effect she will have. I do not think I will give her another dose. Actually, after reading all the posts, I am really worried!

  65. janice says:

    My fifteen year old golden retriever mix did fine on sentinel for many years. On July 7 she had her first dose of Trifexis, and wouldn’t eat by the 8th. By the morning of the 9th she was at the emergency vet shivering and shaking with a fever of 106. Everything normal but a swollen lymph node. After 48 hours of fluids and antibiotics, she recovered. It is now time to give another dose, but I’m afraid. I can’t prove it was trifexis but it sure is coincidental.

    1. joanne says:

      please dont risk your old dogs last years on something that may kill her. I hope and pray you dont give her any more.

  66. Johnny says:

    I have a 2 1/2 yr old Border Collie /Lab, I had given her Sentinel last season and 2 doses this season at which point my vet informed me of the shortage. I tried Trifexis July 1st and she vomitted within 15 minutes , uncertain as to whether it was the extreme heat or what not, I waited until August 1st and tried again along with a meal I gave her the pill and once again within 15 minutes she vomitted. I contacted my vet and without hesitation they told me to return for as refund and exchnage for drops.

  67. Jonathan says:

    So I decided to do my research about trifexis before purchasing and found way to many poor reviews. What is going on is there no way to track reports from vets? Lets say for some reason i purchase this… could i maybe give my dog half of a pill with a meal then the other half a few hours or days later??? Honestly though can’t say i want to try trifexis now.

  68. Jordan says:

    I have a mix of husky and american eskimo who is almost 3 yrs old now. he weighs 25 lbs. We just switched from interceptor to Trifexis last night and he spent all day today throwing up. He seems to be fine now 24 hours after taking the pill, but i am sure he has thrown up everything that was in his system. I doubt i will give him another pill from Trifexis. $140 well spent…please come back sentinel/interceptor.

  69. joanne says:

    I have a poodle mix rescue that I am fostering, when rescued he had been severly neglected. He was groomed and for one month was fine. He was adopted and put on Trifexis. He began to developed a severe skin condition. he has blood work and biopsies done, they seemed to point o allergies. Special food and baths did not help a bit. His skin was so thin that the pads on his feet would wear through walking on pavement. Large dry flakes fell from his fur. His ears scaled, and the skin was so thin the tips of his ears were covered in scab.The vet says it is Pemphagus, but he was fine before the Trifexis. He was put on a daily 10 mg dose of prednisone, and the issues subsided. But Pred is it’s own issue, and I want so badly to get him off of it. I just discontinued the use of Trifexis, after noticing a decline in the condition of his skin within a week of the Trifexis dose. he is now on an oral dose of ivomectin (only) . One month off Trifexis and he is doing well,and I have cut his pred dose to every other day

    1. DrMarie says:

      I’m sorry to hear that your dog is not doing well. It is quite unlikely that Trifexis caused Pemphigus. This is not the type of reaction that we are seeing from other people who are concerned about Trifexis. Sometimes however an autoimmune disease like Pemphigus can be triggered by any medication.

  70. Dawn says:

    I have a six month old male Australian Shepherd, Cooper. He is 40 lbs and has been taking Trifexis for the past 2 months. I gave it to him last month without any problems. His second month he got today. Within 30 minutes he vomited, then seemed to be okay maybe a little lazy. About 6 hours later he vomited again and a few more times shortly after that. Also his stool about 6 hours after was initially normal but runny at the end. He hasn’t really eaten all day and is being kinda lazy, but I wouldn’t say lethargic. If this continues I will be calling my vet in the morning.

  71. dale says:

    I have a 3 year old beagle.he has taken trifexis 2 times.within several days of taking he had a lab seemed to have reduced appetite.two seizures with no history of any prior to taking mind is made up.

  72. Kris says:

    I have a 80lb boxer who has been on the 60-120lb trifexis for over a year with no major side effects. He does sometimes have bouts of coughing up water/spit after taking the pill but that isn’t all that abnormal for him really. He also will sometimes get diarrhea but again I couldn’t 100% say that it was caused by the trifexis. All and all I have been happy with the pill as it has done by far the best job against fleas/worms compared to anything else I have tried. The side effects have been mild at most.

  73. kanmar says:

    It took a while, but I finally connected Trifexis to my ten year old Beagle’s neurological symptoms; excessive panting, rear end weakness and stumbling, constant pacing and licking, weird eye movements and more. These symptoms would last about a week and then vanish, only to return a few weeks later. I was just too stupid to realize that my dog got sick a few hours after taking his Trifexis once a month. When I asked the vet about this she said it was unlikely that Trifexis was the culprit and that my Beagle probably had spinal problems. I wasn’t convinced, and stopped the Trifexis. This was a few months ago, and the neurological symptoms have vanished completely.

  74. Melissa says:

    We have two long haired dachshunds, one 10 yrs old, the other 4 years old. Both rescues. We just started trifexis this month, and so far both of them are fine. They don’t have any adverse symptoms at all.

    We decided to switch to trifexis because of the cost, instead of buying both heartgard plus and comfortis one pill once a month seemed easier and more cost effective. I’m glad we made the switch!

    1. janet says:

      thank you I have a long haired as well and I gave him his first pill tonight. so I am hoping he will be able to take it.

  75. Terri says:

    I am so bummed, wish I had read this first before dosing my dog. I have moved to NC after living in the desert for 25 plus years so I am not used to having to worry at all about ticks nor fleas. Going to a new vet and he recommended this for my 2 dogs. My Cocker/Eskimo mix is 17 and has had bouts of Old Dog Vestibular disease and has started having not-so-great kidney values in her bloodwork but I was assured this med was safe. Today I gave her the second month’s dose with a full meal, and she has been staggering alot today and threw up a few hours later, panting too. I am ready to cry, am at the ready to rush her to emergency but right now I want her to build up her strength and get some rest. Was advised by emergency receptionist to make sure she is getting plenty of water. I am distraught….ready to move back to the desert.

    1. Terri says:

      Oh, she has loose stools too, noticed that tonight. I am going to call the vet first thing in the morning unless I take her to emergency tonight. I will not be sleeping tonight, that’s for sure!

  76. Jennifer Chamberlain says:

    I have a very healthy 8 year old 130 lb. Bullmastiff who has taken Trifexis for the last 2 months, and he has been completely different. The first dose gave him raised bumps all over his body, red ears, lethargy, and irritability. Now a few weeks into the second dose, he has been having trouble walking without tripping. Now tonight he had was looked like an epileptic seizure where he in mid run fell over, and his eyes rolled back in his head. I thought he had a heart attack. After 10 minutes or so, he got up and has been fine since. I know it’s the Trifexis and I will not give him another dose. He has never been as tired as he has been. He even peed his bed, which he hasn’t done since he was a puppy. I’m not usually keen on suing, but that’s what usually has to happen to big companies and get medicines that kill off the market.

  77. Dale says:

    My friend HAD a Chihuahua and a nice spunky mix who used to be about 40lbs.

    The Chihuahua is now dead and the mix breed has had some organs removed and is still doing horribly. Both were fine before the Trifexis treatments started.

    Please don’t poison these animals. Class action, here we come !

  78. Yvette says:

    I have a 4 year old Matipoo (10lbs) This is her 5th dose of Trifexis and I’m just sorry it took 5x to confirm without reasonable doubt that she is having a bad reaction to the medication. Last month when we gave it to her (4th dose), there was a real bad storm coming so we thought she was acting strange because of that. She looks like she is paranoid and on an acid trip! Se won’t eat or drink. She is panting nervously, shaking, confused, kicking her leg out every 15 seconds. This overall crazy behavior! Last month it was similar only a little less intense. We r currently waiting for our 1:30appt to get her checked out but I GAURANTEE you one thing is for sure…. She will NEVER be given another dose! This stuff is horrible! No doubt whatsoever!

  79. Carla says:

    I have an American Bulldog, almost 5 months old. She just has Trifexis for the 3rd time. She’s perfectly healthy, at her normal weight, and full of energy. She hasn’t experienced any side effects at anytime she’s been given Trifexis. From what I can see, it does work well against fleas/worms.

  80. JJ says:

    My min pin, who is 11 years old, was prescribed Trifexis at his annual appointment last year and everything was normal at this appointment. This year when I took him for his annual appointment he had a heart murmur. A 4 or 5 on a scale of 1-6. Could Trifexis be responsible for this murmur.

    1. DrMarie says:

      I really can’t see a murmur being connected to Trifexis.

  81. Victoria says:

    I have two adopted shepherd, lab, chow mixes that are over two years of age. I ‘ve given them Trifexis since they were one. I tried the heartguard (which I love) and the topical flea stuff. I had to stop applying the flea stuff because the one dog (I’m not sure what happened to her as a pup) would roll over instantly and get the oil everywhere. I live in Florida and fleas and ticks are quite a concern here so I needed something that would work. I tried Trifexis and have had absolutely NO problems and NO side effects with either dog. Both dogs get the routine check ups at the vets and both dogs have healthy diets. I’m happy with this product and will continue to use it.

  82. Lizzie says:

    Switched my two dogs (a 4-yr-old miniature Dachshund and a 10-yr-old Whippet mix) to Trifexis after Sentinel became unavailable. Have not seen any ill effects.

  83. nicole says:

    i have a three year old american pitbull terrier who has never shown a single skin allergy. i gave him his second dose of trifexis three days ago and he could not be more different. he has huge red bumps all over his skin, lazy, dazed and confused. not cool. fda is a joke

  84. Stephanie says:

    I have a 3 year old yorkie and 2 year old Maltese/shih tzu. My yorkie started taking trifexis due to flea allergy. It worked so good for flea control, I decided to use on my other dog. My yorkie has never showed any adverse reaction. Tonight I woke up to my maltese mix looking at the ceiling “talking.” (talking as moving his mouth but no sound) He would fall asleep doing this. He was also trembling every so often. He would snap out a little when you pet him but as soon as I stopped, he would start doing again. This probably his fourth dose of trifexis and I gave it around 8:30pm and noticed him acting funny at 1:30am. I tried giving him a treat thinking his sugar was low, but he wouldn’t eat it unless I broke it up. This is very atypical for him because he usually devours them.

  85. April C says:

    I have two 1 year old Shih-Tzus named Oliver and Louie. I have been giving them Trifexis for about two months with no side effects. They are both happy and healthy dogs free of fleas! I love my dogs and wouldn’t want to risk them getting sick from a medicine I have them. The main concern I have is the long term side effect of this drug. Let’s say five years from now, they get severely sick, could I blame Trifexis or not? No one knows that yet since it is a new drug. The first side effect I notice I am going to call my vet!

  86. Steve says:

    Started the first dose of Trifexis to our 18-month Fiest Terrier female (15 lbs), on Friday (17 August 2012). Althought she took the pill without hesitation and did not vomit as other dog owners have reported. Several hours later, she started to be withdrawn from the family and for the next 48 hours she exhibited most of the symptons reported in other posts on this website (depression, diarrhea, no appetite etc). I put out her food this morning (20 August), and she ate like a dog starved. So it appears she is back to normal. IMO, no dogs pain is worth the gain for the use of TRIFEXIS!

  87. Terri says:

    I put my 10 year old Jack Russell on Trifexis 2 months ago. She is allergic to fleas and was TOTALLY miserable before Trifexis. She has had no ill affects of the drug at all. It’s been a miracle for her. I will continue to give her monthly dosage at this time and watch her closely. So sorry to all of you who have had pets suffer and pray that they all get better.

  88. Kevin says:

    Brttany, 40lbs, 10 year-old female.

    My neighbor’s dogs (lab and golden retriever) take Trifexis with no problems; we weren’t so lucky. I gave it with the evening meal. Overnight she threw up. Then again in the morning. By 10AM, she had uncontrollable diarrhea, couldn’t even hold down water, and was shaking (almost like she was cold: shivering). By five PM, the shaking stopped and she was able to drink a little water, but she didnt eat for another day (day 3) and the diarrhea lasted til day 4.
    Bottom line, we’re going back to Heartguard and Advantage. If what you are doing now is working for you and your dog, DON’T change!

  89. Carrie says:

    Our 10-month old, 35-lb. Shorty Bulldog Blue took his monthly dose this morning with his breakfast. 2 hours afterwards, he started vomiting. My husband and I, exasperated by this side-effect called the vet to find out if this is normal. He usually vomits once after taking it, but this time, he’s thrown up 3 times. He’s sleeping it off now, but we’re going to watch him closely to make sure that he doesn’t experience any more symptoms. Reading the stories of other dogs/owners experiences has been eye-opening. Trifexis seems like some scary stuff.

  90. Patty says:

    My daughter has a morkie and called me last night in tears and in a panic because her dog was lathargic and starring at the ceiling. He wouldn’t eat or drink, he didn’t respond when he was talked to and he was trying to stand but couldn’t. She thought he was dying. I jumped on the internet only to find that many people have reported this type of reaction with Trifexis. (She gve him Trifexis about 3 1/2 hours earlier) I told her, after reading what I did, to keep him warm and try to give him water through a syringe ever half hour or so. I also read that it could take 12 – 18 hours to see an improvement in his behavior. Please warn your patients about Trifexis as this reaction is very scary to most pet owners. I’m still waiting to hear if he made it through the night and if he’s OK. I also told her to call her vet in the morning to report this reaction. I think if the vet’s knew this does indeed happen they might not perscribe it without letting the pet owner know this reaction is possible. This was not the first time her morkie had taken Trifexis, but it will be the last. The first few doses showed no signs of a problem, but this time went very badly.

  91. Cheryl says:

    I have 3 dogs. A 10-year old Siberian Husky, a 3-year old German Shepherd and a 1-year-old German Shepherd. My vet gave me Trifexis for all three of them. Within hours of each of them taking the pill with a full meal, the 2-year old became terribly lethargic, which lasted days. If I didn’t attribute it to the pill, I would’ve thought she was dying. Since then, (approximately 3 weeks ago) she’s lost so much weight that she appears anorexic. You can see her entire rib cage. Her symptoms/behavior haven’t been the same since the ingestion of Trifexis. I’ve called my vet and am awaiting an appointment. Since she was a happy and healthy dog prior to this taking this medication, I must say that I believe her current health status is the cause of Trifexis. I won’t be giving any of my dogs this medicine again.

    1. Cheryl says:

      Edit: In my fourth sentence, I meant to say “3-year old” instead of 2-year old.

      1. blake says:

        After reading so many negative and frightening accounts regarding this new drug (trifectis) I am shocked that it is still for sale. Greed takes priority over your pets health and well being in america. Class action is the only way becouse it hits them in the pocket book. I trusted my vet and gave my 3 year old sheltie, max this poison and am just as guillty as the manufacturer and fda. Within 3 hours he fell flat on his face whiile running on a flat surface. Not likely for a dog whose dad was an agility champion. I will hang before I give another dose of this hell to my maxer. He has had bad diarrea for 2 days and has trouble raising up his hind quarters to stand. Very lethargic for his usual self I hope and pray he snaps out of it. His appetite is ok and he is not vomiting but these other symptoms are scarey. Anyone know of a detox procedure available or how long these symptoms last?
        As for those who support and defend this product, get a life!

    2. Cheryl says:

      Update: I took my 3 year old German Shepherd to our regular vet who proceeded to do a physical exam, full blood work and several other tests. My vet said to “Stop the Trifexis now”, in which I have with all 3 dogs. She said she’d be in contact with Elanco (Eli Lilly). My dog is still experiencing weight loss, head tics and stumbling over her feet. (All neurological type symptoms) I’m hoping that as time passes the medication will work itself out of her system. She was such a healthy and happy dog prior to taking Trifexis. My vet also stated that my dog isn’t the first that she’s come across from reactions to this medication.

      1. Cheryl says:

        8 month update on my 3 year old German Shepherd: She’s never recovered. Her blood work has come back fine on numerous occasions however; she still seems to have many neurological symptoms as I initially reported. Head tics, tripping over her feet, etc. (Brought on immediately after the administration of Trifexis) Also, she’s lost so much weight that she looks like she belongs on one of those “starving animal” commercials. (No parasites, worms, etc.) This is a sad situation as the dog was happy and healthy a day prior to the consumption of Trifexis.

      2. Kimberly says:

        Cheryl, how is your dog doing now? Did the neurological signs subside? My dog began experiencing ataxia in hind limbs around 9 months old. He has recently been diagnosed with cerebellar degeneration. His symptoms began as hind leg weakness and then began to show in his front legs. He also had head tremors. I never put it together that Trifexis might have something to do with the neurological symptoms. How is your dog doing now?

  92. Chick Miller says:

    i have an American boxer 3 yrs old about 55 lbs. She has been on Trifexis for 6 months and appears that about a day after giving it to her she breaks out in bumps all over. we have been treating her for an allergy but i am now wondering if this could be a reaction to the Trifexis?

  93. Joanne says:

    I have an 8-year old, 7-pound, Yorkshire terrier. Per the vet’s prescription, he started taking Trifexis a little over a year ago. I gave him his first dose inside a Greenies Pill Pocket treat with a full meal. He ate everything with no problem, but threw up the next day. I reported this to the vet and they suggested for the next dose to give half the dose with a full meal, and then the other half with the following meal. I did this and he had no complications whatsoever. After another month with no issues, I began giving him the full dose with one full meal and still no problems. I just make certain that he digests plenty of food and water along with the pill. My Yorkie has been taking Trifexis for over one year now and still has not had any physical issues or any other visible illnesses towards the drug. On top of that, he is flea-, heartworm-, and parasite-free!

  94. Christy says:

    These comments are all very concerning. I gave my puggle her first dose of trifexis two weeks ago and she hasn’t been the same since. Within 24 hours of taking the medication she was lethargic, febrile, had no interest in eating (which she loves to do), and would just lay in the same spot all day (she is normally very active and his always at my heels, no matter where I go), she won’t even jump on and off the bed anymore. Over the past two weeks, she has become slightly more alert, but remains febrile and is not her normal self. I just hope and pray that she will get better soon and return to her normal active full of energy self. This was her first and last dose of trifexis! I miss my best friend and want her to feel better soon!

  95. Jaclyn says:

    Been giving my dog Trifexis for over six months and no problems. She’s a husky/terrier mix and about 42 lbs. My vet also gives it to his own dogs so that makes me feel better about it too. I always make sure to give it to her after she has a meal and put some peanut butter on it so she’s more likely to swallow it. No problems yet!

  96. Maddie says:

    Trifexis killed my family’s healthy beautiful six-year-old dog, Peaches. After just one dose, her perfectly healthy body began shutting down. We were forced to have her put down after her heart startted failing and she was coughing up blood. She was FINE before…

  97. Martin says:

    I just administered a first dose of Trifexis last night (Aug, 26 2012) 22 month Jack Russell Terrier, Pug mix 16lbs and a 15 month Deer Chihuahua 12lbs. The Chihuahua threw it up about 40 minutes after taking it with morning meal and then seemed fine. I was told to re-administer if vomits within the first hour so I tried again during evening meal and she would barely eat which is very strange so not sure if she got the Trifexis or not and she has loose stool now, but she seems fine at this point. (I feed my dogs a RAW diet, Darwin’s) My Terrier/Pug mix on the other hand, did not vomit but shortly after seemed completely out of it, could barely keep his eyes open, or head up so I let him sleep for awhile. At the first potty break he could barely make it down stairs and then just lay on the ground and wouldn’t move so I figured he was still just drowsy from the Trifexis. The next potty break he was acting as if he was lost and has forgotten how to go and down the stairs, I’m beginning to become a bit concerned now. The next few breaks I had to carry him up and down the stairs and he would just sluggishly walk behind and stopping looking confused. I reach down to pet him and he would whimper down to the ground as if he was in pain. After the walk he would go strait in and hide under the bed too. All of this is very strange for him as he is always energetic in the house and especially on walks, he would laterally dash down the stairs, now he stops, looks around like he is dizzy on top of the stairs, very scary! I’m taking him back to the vets this morning.

  98. Andi says:

    I have two 55 lb female dogs, Sweet Pea (1yr.) and Lily (4yrs.) and had no problems after the first dose. The second dose was a whole other story. Both dogs were literally “out of it” for almost 36 hours. They both acted like they had been drugged… no appetite… and Sweet Pea slept through several pee pees. It scared the hell out of me. I called the company and reported it. The third month, I figured I’d give it a shot that maybe the previous month was just a fluke, but it wasn’t. Same thing… lethargy my rear end… they were dead to the world! I will never use this stuff again.

  99. lauri says:

    I have a 4 yr old boxer/pit mix named Noelani and a 3 yr old APBT named Stanley. They have both been on Sentinel for 2 yrs. June 21, 2012 I gave them Trifexis which was recommended by the vet as Sentinel was unavailable. Stanley has had no problems, however Noelani has had yellow loose stool since she was given the Trifexis. I wasn’t too concerned at first but after a few days I thought it should have cleared. I gave her some pumpkin to see if some fiber would help but it did not. Then we went to boiled chicken and rice. There was a small bit of firming up but not much and was still yellow. She also began favoring her back leg and even refusing to but weight on it at times. Took her to the vets and we are going through different tests and medications. All fecal tests have come back negative for parasites, blood work is spot on. Another blood test being sent out was done today and another new med. If these tests show nothing then we are on to colonoscopy/biopsy. She has also lost 10 lbs. Vet bills are now at $1100.00 and will be climbing. I did change her food to a grain free and the yellow is now gone. Talked to my friend who has been a vet tech for 30 yrs and she said they never recommend Trifexis. She had some Sentinel she had gotten from the company rep which she gave me so at least my pups are back on that.
    I would never ever use Trifexis again. I am so so sorry it was recommened by the vet and that my poor girl is having to go through all of this.

  100. Kelly says:

    My 3 girls (90 lb German Shepherd, 90 lb. Old English Sheepdog and a 70 lb German Shepherd/Chow mix) have been on Trifexis for over a year and have had NO adverse effects at all. They don’t necessarily love the taste. The vet told me to always administer it with a full meal, so I break it up in their food and add either no sodium chicken broth or veggie stock as a treat. They gobble it right down. I’m very very happy with Trifexis.

  101. Craig Delaney says:

    I have a 1.5 year old heeler/husky or Akita mix who has had skin outbreaks all summer (but not the prior). it just dawned on me that Trifexis (switched around May) could be the cause. The poor guy has welts that end up opening up and drive him (and me!) nuts. I plan on discontinuing the use of it after reading other’s responses on here. Will try to remember to come back here to let other’s know of the results.

  102. Nancy Zimmerman says:

    Unbelievable. My dog (7 year old beagle) has a history of seizures and the vet gave me Trifexis anyway. She has had problems with weight loss, itching, thinning hair, and breathing for the last 6 months. Since I moved at that time, we thought the problem might be environmental. We have done a food allergy trial, used steroids, anti-histamines, and I went to a dog allergist yesterday to investigate allergy testing. Though all this the vet left my dog on Trifexis. Maybe because of the food trial, I was able to see an immediate adverse reaction that coincided with her dose a month ago and again this month. Neither vet supported my theory that the problems might be from the Trifexis. But after reading these comments and those on other sites, she is off it and all other treatment for a while. Hopefully she will get better. Poor little pup ):

  103. Janet says:

    I have a 9-month old yellow lab/husky mix. I gave her Trifexis 6 days ago with her dinner and she started vomiting the following morning and she has been vomiting since. We have had this happen once before after receiving Trifexis, but she was only sick for a day. At the time, we were not certain that it was the Trifexis with her being a young pup and all, but we are now certain. I believe she is more sick this time than the last due to her dosage being increased as she just crossed into the next weight bracket at 41.5 lbs. Three days later she was down to 38 lbs. As of yesterday, she has been able to hold down some boiled rice with a little dog food or boiled hamburger. She throws water up every time she drinks though. So far, she is acting normal otherwise.

  104. Janet says:

    Addendum to last post: We are definitely taking her off the Trifexis. If she has any further side effects and starts to incur any further vet bills, we are in for the class action lawsuit also.

  105. Pete D. says:

    I have a 4-month old Lab. My breeder recommended Trifexis. I took Percy to the vet for a checkup on Wednesday, Aug 29 and consulted the Vet regarding Trifexis. Vet said it was a good product too. I wish I had read up on it before administering it to Percy. I gave Percy a dose with dinner on Wednesday night. Thursday morning he threw up when he woke up, and was punky and minimally responsive. At 11:00 am Thursday, I took him to my vet. The vet said initially that it was probably an adverse reaction to the Trifexis and that I should take Percy home for observation. Instead I decided to leave Percy with the Vet for ongoing observation. After several hours of worsening indications, despite having a saline and glucose IV, the Vet did a blood work up.
    Percy’s liver is shutting down becoming necrotic. His liver panel numbers were worse this morning, and now it looks like we’re going to have to put him down this afternoon. The vet called Elanco Animal Health, and was told the situation was likely not from the Trifexis and that it was probably attributable to Xylitol poisoning. Xylitol is found in Sugar-free gum. Well Percy didn’t get into any Sugar-free gum that’s for sure. My wife and I are devastated, and I can’t face telling the kids later today. I feel like the Xylitol thing is a red herring offered by the company, and my understanding is if it were Xylitol poisoning, those symptoms would present within 20 to 30 minutes. We are losing the newest member of our family, and if it’s due to Trifexis this is a crime!

    1. DrMarie says:

      So sorry to hear about your dog. One of the key factors with Xylitol poisoning is extremely low glucose levels. I haven’t seen this being any issue with anyone who has had Trifexis issues, but I’ll look out for it. There is xylitol in a lot of other products as well as gum. I hope Percy is better soon!

  106. Adam says:

    My German Shepherd is 8 years old and has been on Trifexis for over a year. He doesn’t display any sideeffects and it keeps the fleas off all month!

  107. Linda says:

    Oh, now I am really confused and scared. I went to the vet today to get a refill on Interceptor and was told that it is no longer available. The only option they offered is the Trifexis. Looking at the package I see that the dose I was given is for dogs (60.1 lbs. to 120 lbs.). That in itself worries me since my golden is 66 lbs. I had a gut feeling about this drug when I left the vet’s practice today and thought I would try and find some information. Don’t like what I am reading at all. I am thinking of giving it a pass. Don’t know what I will do but am not interested in giving this to my boy. He is a happy, active 2 year old and I don’t want to do anything to ruin that. I might have to take my chances and not give him anything at all. He came into my life last year at 13 months old when his former family surrendered him because he was too much for them. He was on Sentinel when he came to me and this year my vet gave me Interceptor. He had no problem with either drug so I am not going to upset the apple cart now. I don’t feel comfortable or confident about this drug. Any ideas about other alternatives? So worried.

  108. Linda Foster says:

    I have a 3 yr. old female Maltipoo. We had been giving her Comfortis for a year with no side effects and we recently took her to the Vet to get her shots and get more Comfortis. The Vet recommended the Trifexis, so we got that. We gave her the first dose in July and didn’t notice much change other than she had really itchy ears. We thought it wasn’t working since she was scratching so much. We gave her the second dose 4 days ago and last night she threw up after eating her meal and we thought maybe she had just eaten something that upset her stomach, but she has been laying around and won’t play, which is what she constantly does all day. She is lethargic this morning and has thrown up again. She did drink a little water and threw up within 15 minutes of drinking it. When I get her ball to play, she just looks at me and lays her head back down (this is a dog that will play 24/7) so I know she is really sick. I am watching her for a few more hours and if she throws up any more, I will be taking her to the Vet when it opens.

  109. Tiffany says:

    My 3.5 year old female Great Dane started using Trifexis about 3 months ago when my vet was out of Sentinel. I haven’t seen any issues with her. However, the first time I gave my male Great Dane puppy Trifexis at around 3 months of age he got really bad diarrhea for about 3 days. I gave him his second dosage yesterday (He’ll be 4 months old in about a week) and today he’s got diarrhea again. He isn’t lethargic and doesn’t act sick but his stool is like water. This is the only side affect but I think I’m going to research and try to find a different heart worm medication for him. I’ll post another comment if he gets worse.

  110. Gene says:

    I have an 80 lb Golden male.He was getting sentinel before,but I couldn’t get it for a while so after his last checkup trifexis was suggested.He has been on it for 5 months now,and I have to admit that the flea control is superb-however I have become aware of a weakness in his rear that has never been there,and his sleep time has increased by close to 50%.He is an active 6 year old who swims almost every day and is not at all overweight.He swims every day (Florida) and carries huge sticks for long distances.I will not be dosing him again,but I will post again in a month or so as to his ongoing health after being taken off.I realize that we are not vets,but most of us are enough in tune with our dogs to notice disturbing changes.

    1. Gene again-update says:

      I was thinking that maybe I was wrong,and that Buddy was just getting older,but I stopped Trifexis one month ago.In the last three days,he has regained almost all his mobility,and now jumps up for his morning walk with no weakness or stiffness at all.His sleep time is back to normal also.I’m not condemning this product for everyone,but as for my dog-never again!

  111. Kelli says:

    12 year old beagle mix on Trifexis for 6 months now. I noticed that she had started itching, but just thought it was allergies. However, it rapidly progressed beyond any previous skin allergy. Her skin had such a bad reaction, bald spots in multiple locations including her belly, licked herself raw on her legs, red and irritated, nonstop itching to the point she couldn’t sleep at night. Took her to the vet and she prescribed Prednisone for treatment. That solved the problem until the medication ran out and Of course was due for another dose of Trifexis, at which point all the same symptoms came back. I will be taking her back to the vet. She was on Frontline and Heartguard, and never had skin problems like this.

  112. Krista says:

    Last month my 8-year-old spaniel/setter mix died of a sudden stroke…two days after I’d switched him to Trifexis. I’d been using Sentinel for years with no problems. When I went to get a refill, the vet recommended Trifexis. I didn’t want to switch to new meds, because I liked Sentinel, but we have problems with mosquitos and fleas here. So I reluctantly switched to Trifexis. Over the next two days my dog seemed lethargic, didn’t want to walk or eat, and then that night he started foaming at the mouth and compulsively walking in circles, his eyes were droopy and the third eyelids were pulled up, and by the time we got to the ER vet he was blind and had lost all coordination. They told me he’d had a stroke. But he’d been a completely healthy dog! He spent the night in ICU and the next morning had a brain hemorrhage and went into a coma. He went from being a healthy, active dog to an empty shell within two days. Tests showed a bacterial infection in his heart and something wrong with his central nervous system. I couldn’t afford more tests to determine anything specific. I kept pestering the vet that everything had been fine until I gave him the Trifexis, and that’s when he started acting sick, but they said that he’d probably been sick for a while and hadn’t shown it. I don’t think Trifexis was the direct cause of his stroke, but I can’t help but think it had something to do with it. It was just too coincidental that two days after I gave it to him, my otherwise healthy dog was suddenly dead.

    1. Nancy says:

      Our older dog had a stroke and is still with us, his not from Trifexis , our puppy is very sick now after Trifexis . I’m sorry your dog died, wish there was a way to privately contact you here as I don’t want to publicly display my email.

  113. Carrie says:

    Our dog Jack is a German Shepard/ mixed with something elase maybe a lab he is 1 yr 8mo. old. He has always been the picture of good health. He’s a very active and healty dog. He doesn not have hip problems as he just had a check up about a month ago and the vet siad he was in steller condition and said his hip were good. He east Wellness Core dog food (grain-free and protein-focused) it’s not cheep but he absouletely thrives on it. He looks terricfic and his shedding has dropped tremendously. You can just tell he feels good. Anyway he has been on Trifexis for prouably 6-8 months with no issue that I can tell. Until four days ago when I gave hin his monthly dose. A few house later we went for a walk and he was sooo excited because he loves to go for walks. About twently minutes into our walk I started noticing the sound of his nails scraping the sidewalk. After watching him I notice he was starting to drag his back legs a little on the side walk and then he started to do it more profoundly. He didn’t seem to be in any pain but I could tell he was having issues moving his rear legs. It scared me and we imeadetely returned home. I was affraid he would go down and I wouldn’t be able to help him because he weighs almost 50 lb. and I can’t cary him very far. I wet his face a little from the water fountain outside the bank and rubed his back legs a little then we went back home. He seems better now but just kind of lazy which is not really his style. Im not sure if he got sick or not we have a big yard it’s possible. I’m not giving that to him anymore I can’t stand the thought of me giving him something that would do that to him. I have NO doubt that it was the Trifexis that did it.

  114. Jen says:

    Wish I saw these comments sooner. I will never give Trifexsis again. Last night, my 2 yr old Catahoula mix, got Trifexsis. Within a few hours his feet were twitching (almost like he does when dreaming, except he was awake). He was restless and twitching for about 2 hours. Sometimes the spasms also happened on his skin, but for the most part, it was his feet/legs. I fed him some kibble (Orijen) to try and help slow the absorption, don’t know if it helped. He was very lethargic and sleepy today, but no more twitching. I contacted the company and reported the adverse affect. They said this was not a side effect seen in Trifexsis, but there is no other reason for it. He received the medication at 9:30. After relaxing in the living room and then going to bed, he began twitching.

    I saw this same reaction (to a lesser degree) in him last month. I didn’t attribute it to the heartworm medication, but now it makes sense. Last month, it was slight twitches in the feet/legs and some stomach twitching. Looked more like “stomach hiccups”. He didn’t have that this time, but the feet was spasming every 2 seconds for about 30 min straight. Finally, it slowed and eventually he fell asleep. Today, he is passed out and exhausted, but recovering.

  115. Ash says:

    Trifexis is perfectly safe to use, but like all medication is has side effects. Most human medicine has horrible side effects, but yet for generations people have cont. to take the prescribed medications because they truth that their doctor is doing what is best for them. A vet would not prescribe Trifexis if it wasn’t in the best interest of your pet. I have used it on my two dogs 1 is a Beagle-Mix who is 12 almost 13 and my other is a 9 mo. old German Shepherd. I have not had any problems. Vomiting is a quite common side effect, which is why they told you to give it with food. Most “side effects” come from underlying conditions your pet already has, skin allergies, seizures, etc. That is why blood work is so important to get for your pet. So you know ahead of time what could possibly be a problem in the future and get ahead of it before it becomes a major problem. If your reading all this stuff about how Trifexis is a great product, don’t stop using it just because other people are hating on it for believing it caused problems with their dogs when in all likely-hood it nothing to do with the problems.

  116. ruth newsome says:

    I am disappointed in my vet whom I trusted until now it seems they go along with whatever these reps push. Is there a conspiracy to switch us to this product it seems comfortis sentinel and frontline were suddenly not available and we were talked into trifexis. My vet told me it was the same as comfortis with the addition of spinosad and milbemycin. I had had good success with Comfortis which is the same company that makes Trifexis and trusting my vet of 25 years decided to try it. Thank God I did not have the reaction many of you have had but my dogs were itching like they had a million fleas. I called the company 1-888-545-5973 and spoke with someone who gave me a lot of bull about giving the dogs the wrong dosage. My vet recommended the dosage. Then I got a supervisor by the name of Lisa on the phone who was really rude, called me a liar and said I didn’t dose my dogs regularly and that is why I had the problem. I even had her talk with my vet. Still she refused to give me a refund or any other satisfaction.

  117. Sandy says:

    Our 12 1/2 year old golden retriever was put on Trifexis 2 months ago in lieu of Interceptor, which she had always taken without any problem. I was reluctant because of her age, but went ahead with it on the advice of our vet. I was aware of some problems with vomiting in some dogs so when she seemed to tolerate the Trifexis without any stomach problems I thought it was okay.

    About 2 weeks after her first dose we noticed some weakness in her back legs but did not connect that to the Trifexis because of her age, although she has been extremely healthy. She has always had a lot of exercise and runs on the beach and swims every day. The weakness in her hindquarters was accompanied by lethargy and imbalance. I stupidly did not think of the possibility that it could be Trifexis and gave her a second dose. About 10 days later she collapsed on the sidewalk during a short walk. She was able to get up after about 10 minutes, but remained wobbly. The same thing happened each day for the following 2 days. Our vet believes she had seizures. All her bloodwork is normal. It has been 2 weeks since her last seizure and now one month since the last dose of Trifexis. Of course we will never give her Trifexis again. At this point she is improving every day so we are hopeful she will make a full recovery.

    It is possible she had these issues due to some other underlying condition but we are not going to do further testing, especially since she is doing better. The more time that passes without symptoms, however, the more I suspect the Trifexis.

  118. Jennyj says:

    Please make sure you do your homework before giving your dog any flea meds. The main ingredient in comfortis and the the flea control part of the trifexsis is Spinosad, which is the same ingredient in some lawn and plant insecticide sprays. My 9 yeard old perfectly healthy pomeranian-cocker spaniel mix started loosing hair and his abdomen is swolen after his 4th treatment with comfortis. It also took me a while to catch on, but after the last treatment, I saw a specific and definite change in his behavior. Why does all the vets and manufacturers say all the various symptoms, like lethargy, vomiting, tremors, hair loss, etc. Are not related, if there are COUNTLESS internet discussion groups where dog owners are reporting these symptoms appearing in the healthy animals after starting a regimen of spinosad-containing medisyne??? And don’t even get me started on the heartbreaking stories of people who lost their dog within 24 hrs of administering the meds…only for the manufacturer to offer a “free autopsy” and claim the dog had previous liver issues!! My 10 month old Jack Russell had her pre-spay blood work done, only for the vet to call me and say her liver enzymes are elevated, she’s not comfortable spaying here…liver meds..liver biopsy…what!? I dropped the meds, am doing a detox with alfalfa sprouts, garlic, dandelion, and milk thistle. After three days I noticed their noses are wet again, more energy. I apologize to the (minority) of vets out there who truly care about our animals, but I am sick, sick, sick of this money-making business that most veterinarian offices have become! Livier biopsy! After she (the vet) prescribed the comfortis, that, in my opinion, caused the damage in the first place. Comfortis has a warning on their website that their meds might cause “mildly elevated liver enzymes”. Maybe after the very first dose. After that the damage is cumilative. If I can save just ONE dog liver from getting damaged by getting the word out, it will be worth it. Please I beg everyone, do your research, google this stuff, don’t be a victim. You owe that to your dog.

  119. sharon says:

    I gave my 8 year old female golden a dose of Trifexis on August 28th and didn’t notice any side effects. we switched her from a topical flee medicine because it seemed to irritate her skin. On Sept 4th after going to bed she began seizing. I know you said a 3-4 day span is when it is most likely related to Trifexis, but she has never had a siezure before and just had a second one today. They last about 1 minute and take her about a half hour to fourty-five minutes to recoup afterwards. Nothing else in her life is any different. I can’t help thinking that it must be the medicine.

  120. Rhonda says:

    I received a call from my daughter this morning concerning her 11 week old Cockapoo, who became deathly ill 2 hours after taking Trifexis (with a meal). My daughter was very upset and scared as the puppy had thrown-up 6 times wintin a few hours, and was very lethargic (very unusual for this energetic guy), and of course not eating or drinking. I instantly researched the Trifexis “side effects” and came across this forum….wish I would have researched it sooner…we will be making an emergency trip to the vet if his symptoms continue much longer…I’ve read hundreds of horrific incidents about Trifexis here! Doctor, I think you have enough to say that Trifexis is a bad drug and should not be able to be on the market.

  121. Kathy says:

    Trifexis survey. Breed is beagle, purebred, approx 16 lbs, 4 months old.
    S/E First day: vomiting yellowish, thickish bile looking, medium amount. Next day same type vomit but half the amount and after that nothing.
    Dog is about 98% house broken, by the second day pooping all over house, but only had that happen once. He does have access to pool deck and continues to have “accidents” out there. No lethargy, sleepiness, lack of appetite, change in personality. Gave on 9/8/12 and this is 9/10/12. So far today he seems fine.

  122. Janine says:

    I have given my rescue Border Collie mix two doses of Trifexis so far. She is due for the 3rd and I will probably switch back to Heartguard/Frontline or Advantix. She did not have any issues with vomiting or any other dangerous symptoms, but her hair coat has become terrible. She has lost huge chunks of hair… what is left is dull and wirey…and she has some dandruff. Her coat prior to the Trifexis was glorious. She was eating crap food when we brought her home from the foster care and switched her to a top of the line grain-free diet. Maybe the proteins in her food are wrong…i don’t know… but I really do suspect the Trifexis.

  123. Sue says:

    11 year old lab/husky mix. Has taken Trifexis for a year and absolutely no problems.

  124. Darren says:

    I’ve been using Trifexis for six months with my three year-old English Bulldog. The first dose did cause a few rounds of vomiting over an 8-10 hour period. Once his stomach was settled, medication was administered again with half of the tablet given with a meal, and the remaining half given with the subsequent meal. This did help him to tolerate the medication without vomiting, but he continues to be notably lethargic for 36-48 hours, and tends to have loose stools for 24-36 hrs following Trifexis.

    I’ve also noticed he periodically has small pink bumps appearing around his muzzle that typically subside after 7-10 days, though a few have remained along the edge of his lip. I’ve recently realized these bumps are appearing only following Trifexis, and am concerned an alternative may need to be explored to avoid this condition.

  125. Pam says:

    I adopted a 1 yr old boxer in April. He was already on Trifexis so I continued. I have not noticed ANY problems. No fleas since I have owned him.No other problems either. These posts scare me now. I amlost feel guilty to give him another dose. Found this site while googling because I need to purchase more. He has been on it for 6 months now.

  126. Dave says:

    I have a 5 month old golden retriever who has been on trifexis since 9 weeks of age. She has never had a reaction to it.

  127. SpaceDawg says:

    Took my 6mo german sheppard to the vet the day before and was perfectly healthy. Next day, I gave my dog a good meal then gave him the trifexis. 2 hours later he threw up. an hour after that he was dead next to my feet. Something is definatelly wrong with this pill. Sent the dog for an autopsy yesterday when he passed. My bet is that he died due to the pill.

  128. Jenny O says:

    I gave my 2 yr old border/aussie mix a Trifexis last night. Within 2 hrs she was itching all over, and this has continued for a full day. No scratching from fleas, or even signs of fleas prior to the treatment. She can’t quit chewing and scratching. She’s had the pill a few times before, but no obvious side effects until now. Hoping it stops soon because she’s miserable.

  129. Dave R. says:

    I have a 7 1/2 yr old GS Pointer who weighs approx 50lbs, and I’ve owned her for the last 6 yrs. During this time she has Always been on Sentinel with NO adverse effects whatsoever. This year due to the shortage I had to change to Trifexis and have been giving it for the last 5 mos, and have noticed No side effects. I’m not sure if i’ve just been lucky with both, but i’m really inclined to go back to Sentinel!!

    1. Cindy Pittman says:

      I’m with you Dave; we have used sentinel since we got our dog, almost 3 years ago, with never a problem. I am worried about the trifexis; once sentinel is back on the market, I will use it for both of my dogs. Our second one threw it up within minutes of taking it, so we’ve switched to heartgaard for him for now, with a topical flea/tick preventative. I will watch very closely this month as we give our second dose of trifexis to see how they are.

  130. Dave R. says:

    I just want to add, my dog is mainly indoors, and i’m very particular about letting her play with other dogs, as well as keeping her bathed regularly and giving Sentinel/Trifexis at the regularly scheduled time & with Meals.

  131. donna walker says:

    I have 2 dogs, one is a designer breed “cavachon” weighing 23# this was her 2nd dose and my 9 lb. chihuahua both on Trifexsis this is the chihuahua’s 8th dose but always noticed with her to become quiet and sleeps afterward. They both had their meds this evening with their meal of ‘chicken breast’ and after 1 hour BOTH have been laying around and not playing….just sleeping so I KNOW ITS THE TRIFEXSIS flea medicine that caused this. My son quit giving his husky Trifexsis because of the same thing. This is the last time my pets will ever get this product.

  132. Jessica says:

    I honestly don’t know what the ruckus is. My parents have four dogs, Bulldog (75lbs), Aussie (55lbs), Border Collie (45lbs) and sheltie collie (40lbs) and none of them have EVER had an adverse reaction to Trifexis. My family rescued a 5 yr old Belgium Shepard (65 lbs) and Blue heeler rottie puppy (25lbs) and both of them are on Trifexis after failed attempts with most other topical products and the raving review of my parents. Both of them are healthy and perfectly fine and never display side effects. Keep in mind the pill is to be given WITH food. I have to trick my pups (stick in mashed taters and cheese) and follow up the dose with a mix of wet food with their dry food as a treat to ensure their bellies are full!

    With that being said, not all drugs are created equally. Dogs are just like humans – different people react differently to the same medications. You just need to be patient in finding the right meds for your furry children 😉 Good luck, all!

  133. Christian says:

    I have a 1 year old Australian Shepherd male named Denney that is 50 pounds. He has been on Trifexis for the past 6 months and has never had an adverse reaction to it. He is happy, healthy and always flea free. We just got another Aussie girl who is almost 8 weeks named Taylor. At her puppy check-up, our vet wanted to discuss medications for the future, and I quickly requested Trifexis because Denney has done so well with it and we love that it is so easy to keep him safe.

    I think it is terrible that so many people have had to undergo so much stress due to reactions from the medication, but I believe any medication has the potential for side effects and since I don’t really see a pattern in the comments of types of dogs or weights or anything, I think it honestly depends on the individual dog. I also think it is important for concerned “parents” not to jump to conclusions over what they hear on the internet and to trust their veterinarians, as they are the ones with a long history of education in this field under their belts.

  134. christine says:

    I have five dogs. All pitbulls one of them had skin mites that I had to administer oral ivermectin before to treat him. I switched to trifexis on all five. Two years no major side effects. Yes they can drool more and be not as active for first couple of days, but this seems to occur when on the lower side of weight class. For example, 40-60 if your dog weighs 45 lbs more likely to have reactons. Cure split into two doses. Make sure they have plenty of water and food. I give mine a piece of bread worked perfectly. Will always use this med. As for loose bowels it has a wormer in it so yes will occur. Compared to using oral ivermectin this med is a blessing. No having to fight and inject ivermectin on the gums. As with all meds talk to your vet about the right one for your baby. If only give you one option and doesn’t explain how to prevent adverse reactions find another vet. My pitbulls were rescued. One was thrown out of a vehicle one was fought went to three vets 2 said put them down not worth saving 1 said I can save them will work with you. My babies are healthy and well.

  135. Janice says:

    I gave my 15 year old dachshund Trifexis last night. Within 2-3 hours, he collapsed. He could not move, especially his hindquarters. He lost control of his bowels and appeared to be having severe abdominal cramps. I tried to open his mouth to see what color his tongue was to judge if he was getting enough oxygen. His jaws were closed so tight, I couldn’t open his mouth. He was lethargic and in pain. Prior to giving his the Trifexis, he had been fine. I took him to the after-hours emergency clinic. His heart rate was extremely low at 56. He had to be kept overnight and given IV fluids. This morning I went back to the clinic to see him. He appeared to be better, so they let me take him home. The doctor believes that this was possibly a reaction to the Trifexis. At noon, he collapsed again here at home with the same symptoms. I called the emergency vet again. I can either bring him back in and pay for another exam fee or monitor him at home for now. Right now he won’t even drink any water. Tomorrow (Monday) I will take him to his regular vet with all these records. I will never give him Trifexis again, nor would I recommend it to anyone else. My precious dog is just laying there. I hate to see him suffering. This is just not him.

  136. Kobe says:

    This is Kobes third time on Trifectis…..the first time he threw up shortly after, the second time, no symptoms at all….now the third time, we gave it to him in his meal last night, now today, he is crying and lytharic and wont eat. Im very worried about him. He is a 5 year old english cocker spaniel

  137. Stephanie says:

    I have two maltipoos. One male, 5-1/2 years old, 22lbs (he is a first generation) and one female, 3 years old, 10lbs (she is a fifth generation). The first dose I gave them in August made both of them lethargic within a couple hours and lasted about a day to a day and a half. But it also affected my male stronger. He seemed to be a a little confused and just not feeling right. It was mild and I questioned whether it was the medication making him act that way or not. THEN, for the second dose that I gave themfor September, this was very scarey. The little girl did okay and only seemed lethargic for a day to a day and half (like the first time). But the male, he had severe reactions this time. Within about an hour and half to two hours of taking the medicine, he started the following: first, he threw up and then seemed to be not feeling that great. Next, a few minutes later, I noticed he started looking up gazing around the room at the ceiiling. He seemed disoriented and as if he could not focus on anything or was seeing stuff. I sat down on the floor with him and he was weaving his head around gazing into the air and seemed to go into a sort of catatonic state, non-responsive, like he was in a coma but his eyes were open. He was sitting there, I took his front legs and stretched them out so he would lay down but as soon as I let go he came right back up. I tried to get him to stand up but his hind legs seemed very weak and he could not stand and sat back down. So he is sitting there, head pointed upward, staring with eyes open. He slowly closed is eyes. At some point he shifted his weight like he wanted to lay down but couldn’t. I helped him down and he stayed there but would not put his head down. He had opened his eyes barely when I layed him down. So he just layed there, with his head up and staring or gazing off into nothing. Un-responsive. He slowly closed his eyes again. After a little while I pushed his eyelids up and his eyes were rolled up/down, I only saw the whites of his eyes. He didn’t respond. His gums were very light (not normal). At some point he had a full body twitch. I tried to reposition him, but he would immediately go back to the curled up laying down position with his head up. I called the ER vet and they said they couldn’t help unless they saw him so I should bring him in. I recently lost my job and didn’t have the money for the ER so I decided to see if I could get him to respond to me. I started talking to him about treats and asking him if he wanted one. He seemed to start coming around. It was like he was coming out of a coma. He seemed confused, like everything was foggy. But he was interested in what I was saying. So I got him up on his feet and was weak but maintained. I gave him a treat and he took it, ate it. Then several more. He seemed to really be coming around now but was still shakey on his feet. I got him to walk around the room a little bit and he seemed to be getting better. Then I turned on the TV and we sat back on the sofa and watched The Dog Whisperer. He always attacks the TV when other dogs are on there but this time he just growled a little and stayed on the sofa. Then we went to bed and the next day he seemed almost his old self again. The whole “coma” thing lasted three/four hours and maybe would have been longer if I didn’t try to bring him out of it. By a full day to a day and half later he was back to himself again. This whole ordeal was very scarey and I will NEVER give either of my dogs this medication again. It seems to me from reading the other posted comments, that it is a gamble whether or not it will have serious severe side-affects on any dog. I don’t gamble with my precious doggies lives.

  138. Shawn says:

    Trifexsis works great for my 6 year old mini dachshund (10lbs). I did forget to give him his dose for a month or so when we moved, but when I continued with his regular monthly dose he was just fine. He doesn’t chew the tablet though, he usually swallows it whole. I hope that isn’t a problem. That’s what I’m trying to search for now.

  139. Craig in Kansas City says:

    With all outlets being deplete of Interceptor, I found myself looking for an alternative and dosed my two Chihuahuas over a week ago. My dogs, both under ten pounds, experienced none of the vomiting, diarrhea, lethargy, or seizures as others have described. I did give them the first dose after eating their morning meal. As a sidebar, I do cook for my dogs. A pet nutritionist developed the formula which consists of meat, rice, pumpkin, green beans, yogurt, and vitamins.

    However, those looking for an alternative to Interceptor should be aware that the Trifexis did cause reddening of the skin and mild itching in one of my Chihuahuas that has severe allergies controlled by diet. I’m most certain it is the flea and tick treatment included in the Trifexis that caused the problem as this was never an issue with the Interceptor. (Symptoms were as described on the side-effects portion of the Trifexis package.)

    It does beg the question as to why I am dosing my dogs with chemicals for worms when I’m cooking organic food for them. Has anyone discovered a natural de-wormer that could be substituted for a less friendly chemical alternative?

  140. Nikki says:

    We have a rescue pug and she is about 6 yrs old. About a month ago she had a severe seizure. We were scared to death and could not figure out what happened. I just gave her a third dose of Trifexis on Wed and in 48 hrs she has had at least two more seizures. I didn’t know but my parents pug also had Trifexis and almost died, wouldn’t eat, lethargy, and seizures. I am pretty sure now this is the cause of my little pugs illness. Her name is Kaiya and she is an angel. Please don’t use Trifexis!!!

  141. Martin says:

    Gave my 9 week lab/pit/jack russel mix his first dose of trifexis about 8 hours ago. It took him an unusually long time to poop about 7 hours from dose with a full meal. He urinated fine a few times but was lethargic and whiney until he finally pooped 7 hours later. Snooper got back inside and played energeticly for 15 minutes before resuming a lethargic whiney state and finally falling alseep. He did have what I thought was hiccups for a few minutes, but now I am wondering if they were hiccups.

  142. Nancy says:

    I’m up trying to keep my sons10 month old English Bulldog puppy alive til the vet. Opens ! Projectile diarreah , every hour now, mucous blood tinged! Panting, labored breathing, drooling, lost control of his hind legs , can’t walk, have to carry him outside to poop, hydrating with dropper , ice. He can’t sleep for more than 5 minutes after he poops! Had all his shots on time, dewormed, all from the vet who is very good! Was on comfortis for months with no problems! This has happened after trifexis ! Given 5 days ago! No vomiting. I have to watch him, I’ll update after we go at 8am. I’ll email the man who gave it. I have nursed a dog back from a stroke , the heartworm drug in trifexis looks like its causing neurological horrors! I wish I had read this before…. He is our precious grand puppy ! We would have taken him to our county’s ONLY ER vet., but… He misdiagnosed our 13 year old who almost died in his care, then was diagnosed the first day by our regular vet. , stroke. He is not on trifexis and is fine! As for this vet Marie….. Are you getting a kickback from the makers?! For God Sake! I am literally praying he makes it without any permenent damage! And hoping we don’t go bankrupt with vet bills!

    1. Nancy says:

      Just occurred to me, What is everyone’s Lot # on the box? 19100AF ???

      1. Cindy Pittman says:

        Nancy – lot number for our is 06178AF.
        After reading all of this, and the fact that we have done only one month, I’m very leery about giving month number two 🙁

        1. Nancy says:

          Cindy, sorry it took so long to get back, please Do Not give this to your dog again. Not sure what the AF is in the lot # , but going to find out. Our pup survived, after 10 days on persciption food 5 times a day, and a probiotic to balance out the effects of this drug. Vet sent the package back to makers, with a report of his symtoms. Was given a full refund for the six month package, which covered most of the vet bill. He eas also tested for jardia, – negative. I’ll write more below.

  143. Bev says:

    Had our 11month old French Bulldog at emergency vet last night We gave him his 3rd monthly dose of Trifexis in the morning with his meal. Approximately 6 to 8 hours later he was arching his head back looking at the ceiling smacking or licking his lips, He was very tired but would not put his head down for more than a couple of seconds. He could barely walk and would not jump up or down on bed. He started to shiver and shake about an hour after this all started and we decided to take him to the emergency. When we got him to the Vet his symptoms were lessened. But he was still somewhat holding his head up. They took him back into the clinci but we didn’t get to see the Vet for over 2 hours they had some critical kittens they were tending to. By the time the Vet got to examine him his symptoms were gone. She checked him for injury to head or spine and he was fine. I asked if this could be from his dosage of Trifexis and she didn’t think so stating she felt that it was a good safe drug. After 3hours of our arival at the emergenccy Vets we took him home and he seems OK slept through the nite no more holding his head up and back or shaking. Thought I would check the internet for adverse reactions to Trifexis and found 3 posts with the EXACTsymptoms as Henry’s I will be informing the Vet of the information I found here in the testimonials . The more information the Vets have on the adverse reactions to medications they better equipped they are to perscribe or not prescribe medications to their patients. I hope this is the end of Henry’s reaction to this medication and We will not be giving to him again. Our olther dog a Border Collie/jackrussell mix takes heartguard and frontline topical seperately and a few days apart, eHenry will be given the same. Hope this helps someone else who is looking for answers to strange behaviors after submitting Trifexis to their pet

  144. Birgit says:

    I gave my dog Sandi, a one year old Norwegian Elkhound Trifexis to help get rid of fleas. After about an hour she vomitted, began to be very lethargic, blood shot eyes, she could not keep her eyes open and was almost not able to move. She is very active and to see her like this was very alarming. I will never give her this poison again!

  145. Peter says:

    We also have experienced diarrhea with our Boxer mix. She’d taken the first three dosages OK, but the last two have resulted in explosive, watery diarrhea and lethargy. She’s 9 months and 30 lbs.

  146. joy rutledge says:

    my 8 yr old shih tzu was prescribed trifesis, on the 3rd dose she had projectile vomiting, twitching, lethargy to the point I would have to shake her to get her to look at me or focus. This lasted about 24 hrs. and she then gradually improved. I called the co. and was told if it was the medication she would have had problems immediately( it was about 3 hrs after taking the trifexis that this started. ) The med was given with a full meal as directed. After reading all these stories my babies will NEVER be given another dose of thus med.

  147. Bernie says:


    I have a 2.5 year old male German Shepher Dog. He is 75lbs. We had a flea situation when he was a puppy that we were unable to control and ended up trying Comfortis. It worked like a charm. The day I gave him the FIRST chew tab he become very “active/antsy” but that is all I noticed and it have not happened since that one time. When he tured 1 we wanted to get him on heartworm med and my vet told us about Trifexis. He has been on that for 1.5 years with no issues and he just had a year check up and blood work was good. I am very happy with it (although I was upset I intially had to resort to medicine to control fleas). I should mention that we never had a flea problem since. Also, my sister’s dog (a bijan frise) who lives in a county like town has ticks all the time that she has to check the dog every other day. My GSD spends a lot of time there and we camp alot and I have never (not even once) found a tick on him. I know it is not a tick med but that is my observation. I know have a 4 month old famale GSD as well and she will be starting Trifexis in October.

  148. Marilyn Soliven says:

    My dog is a 4 yr old shitzu, poodle she started developing subqutaneous cysts 2 months after starting Trifexis. One actually got large enough to erode through her skin and rupture. She has two other cysts that are growing rapidly. There have been no other changes in her diet. She is healthy and takes no medications.

  149. Judy says:

    My 3 year old Boxer (66 lb) received his first dose of trifexis September 26 at 7 a.m. by 1 p.m. he was experiencing significant side effects. These included nausea, excessive drooling, confusion, unfocused eyes, apparent weakness in hind quarters. We called our vet at 6:00 p.m. when he didn’t eat all of his dinner. About 7:45 p.m. as we were getting ready to take him for an 8:00 p.m. appointment, he vomited. He perked up on the trip to the vet, by the time we arrived there, he seemed to be coming out of it. We decided to cancel and go home. His symptoms all returned and worsened over the course of the evening. And before you all jump on me…Yes, I am aware that sick dogs will often rally when you arrive at the vet. We felt there was little the vet was going to do that we wouldn’t do at home, he didn’t need antibiotics, he just needed to be made comfortable until the symptoms passed. I suppose we could have spent $$$ for IV fluids, anti-nausea meds…but we didn’t. As of 3:00 p.m. September 27, he is still lethargic, ate a small amount of chicken breast, is still somewhat weak…the confusion seems to be diminishing slightly. our poor fur baby has suffered for almost 36 hours and from what I can tell, he probably has about 36 more hours of feeling awful to go. Just to add to the confusion. My 8 year old Golden Retriever (80 lb) got his first dose the same time as the boxer. He had no adverse effects. We will not be dosing with trifexis again.

    1. Nancy says:

      Montra, I cannot put into words how very sorry I am about your dog. I left my story above in September about our puppy we almost lost to trifexis. I had no idea this was poison til I read this site, while keeping him alive til he got to the vet, so please do not feel bad, this drug is still concidered safe. It is not safe. I promise I for one will do everything legally in my power to complain more to these makers. The FDA needs to reexamine this drug. I am so very sorry.

  150. Kelly Ortiz says:


    I have an almost 7 month old Tiny Toy Poodle. We were told by our vet that Trifexis would be perfect for Brutus. So, last month I gave it to him. I broke it in half and gave one half to him with his lunch and the other half with his dinner. The next morning he was shivering and crying. I took him to the vet that morning and the vet told me that he didn’t see amything wrong with Brutus and that he was teething. So, I thought ok… This past Sunday night was his second month of this pill so I broke it in half again and gave him half with this lunch and half with his dinner. Since Monday (the next day) he has been throwing up at least once a day and his poop is like pudding. There has not been one hard poop since before he took this pill. He still eats a little but not the amount he used to eat. I will not purchase a third month of this pill. My poor little dog.

  151. Nancy says:

    Our 69 pound, 15 month old, healthy and energetic boxer, Max, was given his first dose of Trifexis after his evening meal, at 6pm (he was given the dose for 60-120 lb. dogs, which is a double dose when compared to the 40-60 pound dosage). By 10pm, he was too tired to go outside to do his business, but we thought he had an extra busy day and didn’t think anything about it. But, by the next morning, 6am, he was so lethargic, it was scary. Normally he is up, running around and so full of energy. That morning, we almost had to pick him up to get him into the next room. His eyes, which he could barely open, were half-way rolled to the top of his head, and appeared swollen. He would lay there unmoving, and just stare like he was stoned, and I had to coax him to get up to go out. He looked at our steps like he didn’t know how to get up them. His head was very sensitive to the touch, and he acted like it hurt for me to pet him, and he would also jerk his head/twitch uncontrollably every so often. He just looked miserable. We visited our vet that morning, who said he had seen rare adverse reactions to Trifexis such as this. I let Max sleep the rest of the day. He had no appetite and wouldn’t drink, but did not vomit or have diarrhea. I fed him some yogurt, a little pumpkin and spoon fed him water/ice chips. By 7:00 that evening, a little over 24 hours later, he showed some signs of improvement and was eating, but still had occasional head twitching and was still very tired. By 36-48 hours, he seemed to be almost back to normal…he did get tired more easily, but played and ate normally. I will never again give Trifexis. This adverse reaction was too scary to witness a second time…I literally thought Max would not make it and am thankful he is on the mend.

  152. Dawn says:

    Our 10-year-old golden retriever, Buddy, began Trifexis in July when we were unable to get Sentinel. Three days after the first dose, he was lethargic and did not eat much for a couple of days; but I concluded that he was simply sick. On the third day after the second dose of Trifexis, he was extremely lethargic. In fact, he didn’t move or eat at all for 20 hours! At times, he panted heavily. The vet said this is a normal reaction to Trifexis. He said to split the dose next time and to skip a day between the two doses. Well that’s what I did. On the third day after the second half of the pill, we came home to a dog that was breathing heavily, foaming at the mouth (from nausea I presume), and not moving (incredible for even this 10-year-old). It was after 5:00 on Friday (yesterday), and I couldn’t reach our vet. The emergency vet is over an hour’s drive. We washed his face, put the fan on him, and tried to keep him as comfortable as possible. His heavy panting stopped. He was able to stand up at one point, but quickly plopped back down. He was so miserable that we didn’t want to take him all the way to the emergency vet unless absolutely necessary. I sat up with him all night, and he did seem better; but he still did not move. He finally drank some water that I brought to him in the night. He just now (11:00 on Saturday) went out to go to the bathroom (he didn’t walk far), but he could not make it back in – he plopped down on the grass (which is highly unusual). At least that’s an improvement! Buddy does seem to “wince” when we stroke his back. Hopefully, the worst is over and we will avoid the emergency vet trip. Monday morning I’ll be contacting our vet, and of course, we will never be using Trifexis again. I will add that our other dog, a rescued hound mix, has had no ill effects at all. I apologize for being so lengthy, but I hope this is a help. Thank you, Dr. Marie, for being concerned and searching for the truth.

    1. Granny Judy says:

      Three days after the first dose, he was lethargic and did not eat much for a couple of days; but I concluded that he was simply sick. On the third day after the second dose of Trifexis, he was extremely lethargic. In fact, he didn’t move or eat at all for 20 hours! At times, he panted heavily. The vet said this is a normal reaction to Trifexis. This is NORMAL??? Come on!!

  153. Melissa says:

    I have 2 toy poodles that are just about 2 years old. They have been taking trifexis for a year. My female was pregnant with 3 puppies that all 3 died on the 3rd day after she took it. This was due to a misinformed vet practice. I sent my friend up to buy their monthly dose & instructed them to ask about my female since she was preggo. I know there’s only certain wormers u can use on a female whose pregnant or lactating. The recptionist said she didn’t think they could take it. He called me & I asked him to find out what alternative would be safe. Another seemingly more experienced clerk said it would be fine. She took it & started getting sik the 1st day & on the 3rd day delivered 3 puppies who did not survive. I went in the next month & didn’t say why but asked again if a pregnant female could take it. This person checked with the vet & came back & said no. I then told her what happened. A few Wks ago they had a check up & I let the actual vet that sees them know so they could better inform their staff. She told me there wasn’t enough research on it so they didn’t advise a pregnant female to take it. My issue isn’t so much a defect as misinformation. It was really hard to watch my baby go through that. It really is frustrating when I asked bc I thought there may be an issue & it still happened. Melissa

  154. Dawn says:

    8 1/2 yr old female lab/pit and 3 1/2 yr old male boxer/pit both started on Trifexis 3 months ago because of Interceptor shortage. Boy just took first dose of the 61-100 lb dosage 2 weeks ago and has developed the hind leg issues so many others are describing. He can’t even get up on my bed anymore. I have to pick him up. My girl started developing same thing when they were both on the lower dose. I thought it was old age til I was doing research on Trifexis vs Heartguard because Trifexis is just too expensive and I came across all these problems. My girl has been prescribed the higher dose as well but there is NO WAY I’m giving it to her. I’m coping my vet Monday and getting Heartguard. It’s been around a lot longer and I haven’t heard nearly as many complaints. Breaks my heart to see my dogs limping like this.

  155. Dawn says:

    PS…my boy’s appetite is just starting to come back 2 weeks after the dose.

  156. Charles Ealand says:

    I have a 14 month Australian Shepherd who has been receiving Trifexis under vet supervision since I got her at 8 weeks. (Can’t determine when first administered). This occasion it was about 2 weeks between administration and symptoms of seizure. Don’t know if this is the first occurrence or simply the first observation. Otherwise she has been a strong, happy, healthy dog.

  157. kathy says:

    Five months ago we rescued a Malt-Shi. After the first dose of Trifexis, she vomited, but the Vet assured us it wasn’t the RX. So, I’ve still been giving it to her. Every month she’s sick for a day after getting the dose, and every month she seems to be sicker longer, but the vet’s office insists it isn’t the RX. This month she didn’t recover. We found her dead this morning.

  158. Nancy Palestino says:

    I have a 13 year old Yorkshire Terrier who I took to the vet since he was having some sever skin issues and was starting to stink. Since it had been a few years since he has been to the vet, we got him all caught up on his vacines and he received his first dose of Trifexis. The few days that followed he was very lethargic and had some of ‘twitching’ and some stability issues. I atributed it to his age and receiving all his vacines at once….as the month progresses he seemed to be doing better but not like he was prior to the vet visit. Month 2 rolled around gave him his second dose of Trifexis, during the month I noticed he was have some congestion and some clear nose drainage, I figured it had to do with allergies and continued on his over the counter alergy meds. It is now time for his third dose, I take him back to the vet due to the congestion and alergy issues, they put him on some different meds to treat that, and he takes his 3rd dose of Trifexis, for the first couple of days he is super lethargic and his having the same twitching and stability issues, and in a matter of two weeks has lost all eye sight. I don’t have any proof that Trifexis are causing his problems, but I have since taken him off ALL medications and he will not be receiving any more Trifexis. Due to a limited income I cannot afford to keep taking him to the vet and tring different alternatives….all I know is we were dealing with some simple skin allergies due to an allergic reaction to flea saliva and now he has a hard time getting around is blind, seems to me there is a connection. I’m going back to Advantage and Heart Guard, he has taken them both in the past and has done very well with them.

  159. Hank says:

    Our 16-month old very healthy Chiweenie (10 lbs) threw up and had diarrhea after taking Trifexis. We wish we had read the problems reported here…. We think he will be OK, but no more Trifexis, and the vet is getting a very angry visit.

    We need to end the patent protection immediately for companies that can’t supply their products in a continuous stream! Trust me – that will fix a whole lot of supply problems!

  160. Melissa Peters says:

    I gave my 5 lb Yorkie and 5 lb Chihuahua their monthly doe of trifexis on 9/16/2012. My Yorkie was 13, my Chihuahua 12. Just 3 weeks prior they had gotten a clean bill of health from the vet!
    In 1 hour after taking the pill after breakfast, my Yorkie was struggling to breath. By lunch we were on our way to the vet. Sweeties lungs were half full of fluid and she suddenly had a heart murmur! Xrays were taken, lasix, Penicillan, and Benedryl were administered and I kept her on oxygen all night. Back to the vet next morning to be told she had a level 4 out of 5 heart murmur.! I was totally shocked! They could keep her on Lasix and a couple of heat medications but it would take time to adjust the meds and it MIGHT give me another year with her. I made a hard decision that day for my Princess. 2 days later my Chihuahua can’t walk! Folding his paws back and trying but looks like he’s drunk and falling. Not able to get up, Started in his right front paw, moved to back right, back left, front left. Then same breathing problems show up. Off to the vet I go again! Pneumonia and a neurological problem. This time the vet agrees it is the Trifexis and calls the manufacturer. Evanco states they have no reports of these side effects but will pay for his treatment! Really? Why would they pay if they are not guilty of marketing a product without ample testing? 2 dogs in 1 week? He is still not able to walk or breathe right and vet still sees him every day. AND Trifexis raised his liver counts as someone mentioned above. This product should not be on the market,

  161. Amelia Quattrociocchi says:

    Hi Debbie !! I have a Jack Russell and I am having the same problem with him He has bald spots all over his body and i go and pet him and bigschunks of his hair come off.. He was fine until we started giving him the Trifexis.. I really would like to stay in touch …

  162. sUSAN says:

    I have a one year old cavapoo who has been on Trifexis since he was about 6 months old. He has had no reactions or side effects to it at all. He is now just over twelve pounds, so he is taking the dose for a 10-20 pound dog. The only reactions he has ever had to medications were to the 5-in-1 shot that the vet gave him when he was about four months old and those were minimal, although my parent’s short legged beagle went in shock after having it. I guess it all depends on the dog, just like human medications affect every person differently.

  163. Liz says:

    We rescued a 4 year old chow mix in May from our local shelter. The vet recommends trifexis which he has been on since May 25th. He seemed ok until this month . 3 days after giving him trifexis (with food) he had a serious seizure. We don’t really know our dogs history since he was a stray from the shelter but we have not known him to have seizures. When I heard that dogs prone to seizures should not be giving trifexis I decided to research it. After reading everyone’s comments, I feel positive that trifexis is the reason for my dogs seizure. I’m pretty upset about this drug as wish I was at least told about the side effects. I’m just given a pill in a sealed pouch. I’m never giving my dog this pill again. It makes me sick to read about dogs being so sick and even dying from this poison.

  164. Bette says:

    I posted a comment approx. two hours ago re: Triexis and my Yorkie. Why hasn’t it posted?

    1. Bette says:

      It has been one month today since my Yorkie died, of what her Internist also believes was the Trifexis. I am so totally hearbroken. I would give anything I own to have her back. I owe it to my little sweet Abbie to make all of you aware of these circumstances .

  165. Martin Day says:

    I adopted an older border collie, Ozzie, six weeks ago. His age was estimated to be 11 or 12. He had been fine apart from occasional stiffness in his legs after getting up but that would disappear after he had taken a couple of steps. I gave him Trifexis on October 1st 2012. This was the first time he had been given it. The next day, on several occasions, his legs splayed out a little as if they were about to colapse. For the next 2 days he appeared to be fine, This morning, October 5th, he cannot get up from a lying position. I have called my vet’s office and they said to take him in. Unfortunately I cannot lift or carry him so I am waiting to speak to one of the vets. He doesn’t appear to have any other symptoms but my poor old man is trying even now to get up but cannot.

    1. Martin Day says:

      Follow up to my previous message:
      I took Ozzie to the vet who said that the problem was neurological. He said that Ozzie’s eyes had the appearance of a dog coming round after anesthesia and he would treat him with steroids. He also said that he would call the manufacturers of Trifexis and see what they had to say as it appeared to be too much of a coincidence that Ozzie should be affected like this for the first time after taking Trifexis for the first time.

      1. Granny Judy says:

        Martin, you are fortunate to have a vet apparently willing to pursue this. Hope all worked out alright.

  166. Natalie says:

    I had a very forlorn, skinny stray show up in my driveway. I took her into the vet to be tested for heartworms and other parasites. She came back negative for heartworms and I was thrilled to just be putting her on preventative. Vet recommended trifexis and I said sure (on other dogs I’ve used heartgaurd and advantix without issue). This poor stray, who was in very bad condition to start out with, is now extra lethargic, shaking and shivering when shes is not cold, has lost her appetite and is in worse shape than when she showed up at my house. She is about a two year old, boxer mix (29 lbs should be 45 to 50 lbs) and the symptoms began 30 minutes after treatment and have continued over 48 hours after dosage. This is lame, I feel so bad, I should have stuck with tried and true medications- nothing like accidentally poisoning a dog you are trying to help. I will not be administering trifexis in the future to any dog.

  167. Elaine says:

    I have two dogs: a 7 year old scottie x mini poodle and a 1 yr old shih tzu. Both received Trifexis at the same time and within hours started chewing themselves raw. It’s been 3 days since their first dose and all they do is scratch. The shih tzu has also been vomiting and experiencing prolonged periods of coughing *only* since she took Trifexis. The Trifexis was prescribed after their annual exam and no known health issues for either. I will not be giving Trifexis again.

  168. Lisa says:

    Two of my pugs are having adverse reactions with in 12 hours! Frank is 13, he is very lethargic right now. Fiona is 4, and she has no appetite and is lethargic. She lives for food, but will not touch it! Should I take them to the vet? Or wait for the effects to wear off?

  169. Judy Shuman says:

    Jack was my first dog, a magnificent blonde Golden Retriever. He was my constant companion. He “worked” as the therapy dog for my wellness medical practice, where he offered his own unique stress management therapy, lowered blood pressure and lavished unconditional love and acceptance on each person who came through the door. He was the picture of the perfect Golden, with no health problems, loved chasing squirrels; calm, gentle, always smiling, his “heads up walk” a reflection of his Grand Champion heritage always smiling, tail wagging and obeyed my every command. Jack was the perfect dog!
    On May 11, 2012 I gave Jack his first and only dose of Trifexis, beginning a cascade of health problems that led to his death only 3 month later.
    In less than a day after taking Trifexis Jack was vomiting, very lethargic, confused and could hardly walk. I rushed him to our family vet where lab work revealed that his liver enzymes were “off the chart”, white blood cells were extremely high along with abnormal levels of most leukocytes.
    Our vet said that Jack’s liver was shutting down and his immune system was not able to handle the onslaught.
    It was a miracle that Jack survived the toxic attack upon his liver and immune system. He slowly improved and within a month he was up and about. However, he was still “off”. He was far less active, tired easily and his appetite was getting worse and worse. My happy, energetic dog had lost his zest and passion for living.
    In mid-June I noticed just the slightest limp in his right rear leg. His limp began to worsen, so that after one-week of rest and conservative care, we headed to our family Vet. A torn ACL was the preliminary diagnosis and just to be sure, Jack was seen by a certified veterinary orthopedic surgeon. The surgeon was “99% sure” he had a torn ACL and recommended immediate surgery. We opted to start with conservative therapy, rest, and knee brace. Two weeks later Jack was worse and his pain was increasing. Our Vet recommend that we take Jack to the University of GA Veterinary Hospital for evaluation.
    We never made it to the appointment. Sunday, Aug 18 every thing went totally downhill for my Jack. He began with a nosebleed that just would not stop. Monday morning we rushed him to Emergency services at UGA where he was immediately admitted to ICU.
    On Tuesday we got the devastating diagnosis that Jack had aggressive metastatic osteosarcoma. My best friend and companion, the gentle dog who brought love and comfort to me and hundreds of our clients had tumors in his knee and ankle, three tumors on his lower vertebrae, tumors on two ribs and the cancer had spread to his lungs and nasal cavity. I brought Jack home, held him all night, stroked his beautiful fur and told him a thousand times that I loved him. Wednesday morning, surrounded by a family who loved him and the staff of our Vet office who tried so hard to save his life, Jack died peacefully in my arms.
    I am left with so many unanswered questions. How could my beautiful, champion pedigreed dog, with no family history of cancer, go from happy, healthy to ravaged by metastatic cancer in just 3 months?! I am so angry!
    Finally after numerous discussions with my vet and scouring the internet for information, reading everything I could about Trifexis , we have come to the conclusion that the liver inflammation which occurred immediately following Jack taking his first dose of Trifexis, severely compromised his immune system. The lymphocytes and natural killer cells which destroyed cancer cells, creating the balance that protected Jack from illness and helped him heal could not function properly. I know this is what happened, Jack was not the same dog after Trifexis. Trifexis caused the severe liver inflammation which created the immune dysfunction that allowed the aggressive cancer to invade and destroy my Jack.
    I can’t change what happened to Jack. Jack trusted me with his life and how ever unintentional, I let him down. The least I can do is to warn others of the dangers of Trifexis. The time we have to share our lives with our pets is not nearly long enough, we certainly want to make sure that we don’t inadvertently shorten the time even more.

  170. Rueben says:

    Dexter is 3 year old Westie, weighs 18 pounds, Been taking this pill for close to a year; no fleas, no heart worms, NO SIDE AFFECTS. tHE PERFECT PILL FOR HIM. OF COURSE NOT DOGS CAN TAKE IT. USE WISDOM!

  171. Pat says:

    My 11 year old Rat Terrier is having trouble with Trifectis. She has been on Sentinel (which was great)all her life, but they are having production problems and when it came time to re-buy the Vet did not have and suggested Trifectis. She is borderline on the weight so they suggested the next dose up. She is on her 2nd dose and has trown up numerous times, she is very shaky and wobbly, loss of appetite. She walks slowly all srunched up, it breaks my heart to see her like this. The 1st dose was mild side effects, no vomiting, but some muscle issues, the 2nd dose is the worse and the effects are lasting longer. I am giving her smaller amounts of canned food w/water like soup more offten to make sure she stays hydrated and fed, that seems to be helping. I will not do this to her again! Both times she took with food.

    1. Pat says:

      This is in reply to my own post.
      I took my dog to the vet and she had cancer of the spleen. This was what was causing her symtoms.

  172. Ginny Sengewald says:

    My 22 month old Boxer has been on Trifexis for a year with no problems. This month I gave her her pill on a full stomach, however the food was different. Instead of Dog Kibble that she had been on, she was eating hamberger, rice and pumpkin. After I gave her the pill she vomited everything up at least an hour after taking the pill and then continued to vomit six or seven more times. I took her to the vet who did a blood work up and gave her a shot for the vomiting. Her blood work came back with a very high liver enzyme count.

  173. Hali's Mom says:

    We’ve experienced many of the adverse side affects with our two year old Cavalier King Charles Spaniel. She weighs about 20 lbs and was given Trifexis in the dosage range for 20.1-40 lbs. We dosed her with her afternoon meal around 3 pm. By 10 pm, she was exhibiting severe lethargy and unspecific pain. She has been in bed with us for over an hour prior to these symptoms beginning. Her gums were normal color indicating that her circulation was good, but her breathing was labored and her sleeping so deep that we could not wake her. When she did rouse up, she was very thirsty, but could not lap so we used our fingers to get enough water into her. That seemed to help her.

    This morning she is still very lethargic, but ate a small breakfast and did her usual morning chores outside.

    Wee were up all night just watching her breathe with much anxiety about how she was. Thanks to this website, we realized that she was probably just going to have to endure being in pain and uncomfortable until the drug wore off.

    She is better this morning, but we are going to report all of this to the vet who recommended this drug to control fleas. This is a BAD drug….don’t give it to your dog!

    If our dog still has more symptoms as the day progresses, I will post more information. My heart goes out to all of you who have had the same or worse reactions to this terrible drug.

    1. Hali's Mom says:

      I failed to mention that Hali weighs 20.6 lb so she was dosed with the drug for 20.1 to 40 lbs.

  174. Cindy Pittman says:

    I gave our foster dog, a one year old ~13 lb shih tzu, a trifexis tablet, and he vomited within 20 minutes. Your instruction to give him another tablet did not sit well with me… if you throw up something, giving more does not seem to be the solution. Plus, these pills are very expensive! Our 2.5 year old Pomeranian chihuahua, 12 lbs, took his pill fine, with no issues.

  175. Mae Ann Shillings says:

    *6 month old, Malti-tzu, weighs about 6 lbs. *has been on Triflexis for 3 months
    After the first 2 doses with no noticeable reactions, I gave Bella her 3rd monthly dose on 10/2. 4 days later she spent an entire day lethargic, no appetite, vomited a thick yellowish bile looking liquid 2 times within a few hours, & 3-4 times that day passed poop that appeared to have blood in it, followed by several bouts of diarrhea. I had been noticing a slight difference in her behavior over the last several weeks, but thought it was just “puppy” phase… She sometimes acts as if she doesn’t “know” who we are or is “afraid” of ordinary objects that she has been exposed to numerous times. I am well aware of the risk of side effects from any medication, however I fear that her symptoms sound strangely familiar to many of those listed here. I don’t think we will continue with Triflexis. Does the company offer a refund for any unused portion of a 6 month supply if the customer is dissatisfied?

  176. Ann Olsen says:

    We gave our eight pound, 11 year old, miniature rat terrier trifexis around 5 pm last night. It was her second dose (first does was approximately two months ago with no problems that we are aware of). We were away from home between 6pm to 8pm. When we returned, our dog Charlotte had very disturbing symptoms: crowning of her neck (would stretch her neck out with head held high), ears drawn back, eyes bulging and twitching, lethargic, confused, uncoordinated. She has very distinct ways of communicating and interacting with us (paws at our face reacts to words we say, very active, runs around, sits in certain spots). She was non-responsive and non-interactive and continued the crowing of her neck with her eyes bulging and ears drawn back. We were terrified. We called poison control and at the same time drove to the ER Vet around 10 pm. Poison Control said that the reported side effects of Trifexis are mild and they don’t believe this is due to Trifexis. The reactions reported by people above and on other internet do not sound mild. I have no idea if some of it is negative propoganda from competitors but come on!!!Some of what we have read online is unbelievable accurate and similar to what was happending to Charlotte. The description of the crowning of the neck by others online along with the lethargic behavior and confusion was spot on. The vet proposed two courses of action: 1) keep her overnight on IV fluids (she explained that her reaction is neurological and the IV fluids would help flush things out) or, 2) inject her with fluids under the skin and let her go home if we stayed up with her and monitored her for seizures with the understanding that if she resumed stretching her neck out or any of the other symptoms we would bring her back in. Please note that by the time the vet saw us it was around 11:30 pm to 12 and Charlotte was a little bit more herself. The vet was concerned that her positive behavior at the clinic could be due to addrenaline and that once we returned home we could see a relapse. We returned home and Charlotte continued to improve. It is now 9:15 am and we are hoping that these symptoms don’t return.
    Is there any risk of these symptoms returning? How long does the medication stay in her system? I’m not sure if I’m asking the right questions.
    We will return the remaining medication we have and will not be using it. We have a miniature schnauzer and she too received her 2nd dose yesterday with no problems. What we saw Charlotte go through was so horrible and scary, we are just not willing to take that risk for either of our dogs. The ER vet indicated that there hasn’t been enough testing or research on this medication to know what causes this reaction. She indicated that she’s seen approximately ten cases like this. We were furious and disppointed last night and can’t believe that this is being sold without more of a warning. We are willing to share our ER vet records to validate and support the feedback we are leaving.

  177. katie says:

    I’m so glad to read some of these posts.. I thought i was going crazy trying to figure out Charlie’s problem. He’s a 3 year old pit mix. We started on Trifexis 6 months ago and i did notice the vomiting on a couple of occasions, but what has just recently started is the red bumps, red skin, inflammation, ITCHY ears! He smells funny, too. Kind of strange. I’m obviously not going to continue use, but what do I do to treat/detox what’s already been done?

  178. Lee Laughlin says:

    I belive trifexis has made my 18 month old golden retriever very sick (vomitting and listless), and I encourage dog owners to avoid this medicine.

  179. Erika says:

    Just tried Trifexis for the first time. Two dogs unaffected, one threw up immediately, one threw up the next morning and was a bit lackluster, one lost appetite for a WEEK. I’ll be returning the remainder; this doesn’t strike me as a cost-effective approach to controlling flea and heartworm problems. And needless to say I dosed the immediate vomiter with something ELSE later on. I’ve had good luck with Heartguard or similar for preventing internal parasites and Advantix for external, as in this area ticks are a concern anyway.

    1. Erika says:

      Postscript: the barfers were mostly-Pit mixes, the no-appetite was a Shiloh shepherd. The full shepherd and the golden mix were apparently fine. Sounds like quite the household, doesn’t it?

  180. Abi says:

    I have had no problems with the product and have been using it for years on 4 dogs.

  181. Marissa says:

    I’ve been givin my dog, a three year old golden retriever trifexis since April with no problems. He had previously been on consortia and heart guard plus, also no problems. He won’t take it as a treat though, I have to crush it up and put in his food.
    Happy with this medication!

  182. Lisa says:

    I wish I had researched this product but like most of you I went on vet recommendation. It wasn’t until yesterday when one of the techs said “it should be safe to give her, I’m sure it has nothing to do with her condition.” Now after reading these I’m not so sure and she WON’T be getting her next dose. About 7 weeks ago my dog (a pit bull mix, female spayed 3 years old) suffered from twisted gut for a lack of better terms. After an emergency surgery later (we still don’t know exactly what caused it) we thought we were in the clear. On Sept. 24 we picked her up from the vet after having her sutures removed. We were told she could eat her regular food and mix it with the special diet. Plus it was ok for her to have her heartworm meds. I had to force it down her but she took it. 15 mins later she is outside throwing up and had to be run to an emergency clinic where they decompressed her stomach twice and pumped her stomach. I thought it was the food……Maybe not.

  183. Walter says:

    I have a Great Pyrenees named Gracie, aged 14 weeks. Someone had dropped poor Gracie out at my home. She was covered in fleas and diagnosed as anemic when we took her to the vet. She was having seizures to make matters worse, likely caused by the anemia. We have just completed treatment for seizures with Grazcie. So far, she is doing fine, however we took Gracie back to the vet for a followup to the anemia/seizures. As we left the vet’s office, we were given Trifexis to get Gracie started on. WHY on earth my vet was not aware that this drug is NOT supposed to be administered to dogs with seizurtes, I’ll never know. Gracie is ok so far – it has been three days since I gave her the Trifexis. I only wish that I would have researched it BEFORE I gave her the dose. After reading the horror stories of other poor dog lovers who have inadvertently caused pain or death to their animals, I will NOT be giving Trifexis to ANY of my now six dogs that are a part of my family. And Dr. Marie, anything that kills just ONE animal is not suited for sale to the general public. I WILL tell everyone I know NOT to give Trifexis to their dogs. I will also let my vet know about the many horror stories online — if they haven’t heard – I think they are all TRUE. I haven’t just fallen off the banana boat, either. I’ve been blessed with many, many loving animals over my lifetime. Many, many vet trips. I will not lose ONE to some crap like Trifexis, if I have to pick the fleas off my pups one by one. I’ll go back to what I used before this garbage.

  184. Mae Ann Shillings says:

    Just returned from having Bella spayed & her liver enzymes are elevated!

  185. Corinne says:

    My 14 lb. , 4 year-old Pomeranian has been on Trifexis for one year with no side effects. She is still very healthy (except for a fish allergy) and pretty energetic. The vet did check her for heartworms prior to prescribing Trifexis. She was on Frontline Plus prior to Trifexis, but due to the amazing amount of hair and her daily walks in the park, she got fleas within 3 days of treatment with Frontline. All these reports are very worrisome. I feed her the pill in Natural Balance Venison and Sweet Potato Limited Ingredient canned food, if that helps.

  186. Vince says:

    We have a three year old shichon. Addie is three years old and has never had any health issues. We had been giving her sentinel until it became no longer available. our vet recommended Trifexis 3 months ago. Upon first dose she became very lethargic , starring off into space and confused. We called our vet and they indicated that the side effect was not serious and to continue with the trifexis. The symptoms passed within one day and we gave another dose the following month with the same symptoms. The vet continued to indicate it was safe. We then split the dose over two days in the third month. This lessened the symptoms but within 10 days she experienced a seizure . We took her to the vet and ran a blood panel that indicated elevated liver enzymes to the point the vet suggested a 900.00 ct scan and recommended a medicine to help her digest protein that she would need to take for the remainder of her life. We are not following this advice and feel that it is directly related to the trifexis. We will run a liver panel in 30 days when the trifexis has had time to exit her system. We would never use this product again and will post what the panel reveals in 30 days.

  187. Lorraine says:

    I have an 1 year old dog (part Chihuahua, part Pomeranian). Trifexis was the only flea medicine I ever had her on ever since she was old enough to take it. I never noticed any “bad” side effects other than her scratching. She doesn’t have fleas but she was scratching so much. So I took her off Trifexis to see if it the cause of her scratching. Her scratching isn’t as bad, she barely scratches now and she isn’t on any medication. Now I’m afraid to put her back on Trifexis because I think it was too potent for her. She’s 6 lbs and she was using the correct dosage (5-10 lbs). I just don’t know why she scratched that bad.

  188. Lorraine says:

    I have a 1 year old dog (part Chihuahua, part Pomeranian). Trifexis was the only flea medicine I ever had her on ever since she was old enough to take it. I never noticed any “bad” side effects other than her scratching. She doesn’t have fleas but she was scratching so much. So I took her off Trifexis to see if it was the cause of her scratching. Her scratching isn’t as bad, she barely scratches now and she isn’t on any medication. Now I’m afraid to put her back on Trifexis because I think it was too potent for her. She’s 6 lbs and she was using the correct dosage (5-10 lbs). I just don’t know why she scratched that bad.

  189. Clewis says:

    My yorkie (3lbs, 1.5 years old) wash oven this yesterday.
    I was a bit concerned as the packaging stated for dogs over
    10lbs but the vet asked how much he weighed and gave this.
    My dog became lethargic, shivering and twitching most of the night.
    Looks at me as he is drawn up and shaking. He also has labored
    Breathing and I started surfing the web to see what reviews are out there
    On the med. He has taken interceptor and confortis for past six months with only one
    Vomit episode (when he ate it in empty stomach).
    I am very concerned I have harmed my dog with my vet’s

  190. Kristy says:

    Shih-tzu, 11 yrs old. CONSTANT itching and scratching and ear infection as a result…started within a day of taking trifexis the first time. Will not be continuing with trifexis. Had itching and ear infections with Heartguard in the past, but never Sentinel or Interceptor, so probably allergy related. Whatever the different ingredient is, my dog must be allergic. He had a smelly painful ear infection for 4 years taking heartguard before the vet finally realized THAT was causing the ear infection (yeast). yikes. hope this helps someone else

  191. Alisa weaver says:

    I gave my 60 lb boxer and 55 lb pit bull a dose of trifexis. The next day my pit acted very lethargic and didn’t want to eat. She was fine the next day. My boxer had no reaction at all., so I really didn’t relate her symptoms to the medication. I gave them both a second dose last night and my boxer is acting very lethargic, shakey when he is standing and not his usual self. I know it is the Trifexis that is causing these symptoms. I will not give this to them again. I hope the word gets out to the public to stop using this stuff.

  192. Sammy says:

    We have 3 Havanese dogs, a 4 year old, a 2 year old and a one year old. Trifexis works for us. We have experienced no side effects. No problems !

  193. MJPeters says:

    I gave the 2nd month dose 9/16/2012 to my 5 lb 13 yo yorkie and 5 lb 12 yo chihuahua. On 9/1/2012 both were given a clean bill of health by my vet. Within 1 hour, Yorkie could not breath. Vet found Yorkie had pneumonia and heart murmur. Treated with Lasix, antibiotic, prednisone and benydryl. She died the next morning, 9/17. 9/18 the chihuahua could not breath and could not walk. vet found he too had pneumonia, a heart murmur and did not know why he could not wallk. Treated him with lasix, antibiotic, prednisone. He made it until 10/18 and couldn’t fight it anymore. Breathing never improved although xrays showed pneumonia was gone. He never regained the used of his front right leg. 2 dogs in 30 days. This shoud never have been put on the market.

  194. Sean says:

    I have an 8 month old boxer mix, roughly 60 pounds. I took him to the vet when he was old enough for his first series of shots and he had a lot of fleas. I inquired about trifexis and was told at the time he did not weight enough so I was given revolution. Helped a bit with the fleas but not intestinal parasites. He began to lose his fur and had very flaming skin. I found out in another visit that he was having a reaction to flea bites. He was of proper weight at that time and we put him on trifexis and an antibiotic and within two weeks his skin was clear. Within 24 hours fleas were gone and he was parasite free at the next vet visit. He has been on trifexis now for 4 months and has had no side effects. Be sure to check with your vet since like most flea control and parasite control meds. Trifexis is weight specific. The more or less a pet weighs depends on the sidestep amount. To much could lead to problems as with any medications.

  195. Crystal W. says:

    We have an energetic two-year-old boxer. He weighs about 62 pounds. The first dose of trivexis he received was for 60 – 100 pounds. He was very lethargic the first day and his eyes were red and droopy. He seemed to be better the next day. When I expressed my concerns to the vet, we decided to play with the dosage because Pup-dog’s weight is right at the limit. He received the next dosage down, 45 -60 I think, and had no symptoms this time. I was not going to give him anymore after that first pill, but I feel much more confident after going with a lower dose.

  196. James Maldonado says:

    I gave my two-year old Australian Labradoodle Trifexis and within six hours, he was lethargic with no appetite and was wobbly on his feet. Best description would be that he looked “zombi-like.” He was extending his neck and nose into the air, would not open his eyes or walk and was generally out of it. Called 24 hour clinic and they said to monitor and bring him in if necessary. Stayed up with him all night and he seemed to snap out of it at the 12 hour mark after ingestion.

  197. Harmony Raymond says:

    I gave my 5 year old yorkie trifexis on sat night.. she woke me up at 4 am trembleing and confused as she was shaking to death.. I monitored her for a bit and tried to get her to eat.. she ate (only because it was her fav wet food) and aftewards she immediatley threw it all up.. she was still shaking and finally i thought it was over but she wouldnt walk or stand up. She was so lethargic it was scary and i had to keep checking to see if she was alive.. i immediately rushed her to the vet (that gave me the pill) and they put her on an iv and she is doing better now.. THIS SHOULD NOT BE LEGAL and should be pulled off the market… yesterday was so scary and not to mention EXPENSIVE. Trifexis is to blame.

  198. Ev says:

    I gave my 14 year old Jack Russell Terrier a first dose of Trifexis 3 days ago. She vomited it out the first day. Then I redosed her. She did ok the second day, but today, she started wheezing for periods at a time. It looked like she was having a heart attack or something. These attacks are short, deep breaths as if she is gasping for air and they occur for about 30 seconds at a time.
    She never had attacks like this prior to Trifexis. Anyone observed these symptoms in their dogs? I have to take her to the vet.

  199. Shari says:

    I have 4 dogs and 3 of the 4 became lathargic and lost apppetites for a day after giving Trifexis. I have given them the Trifexis all summer and it seems to make them feel bad for a day. I like the idea of one pill for fleas and heartworm but next season I won’t be using Trifexis. The dogs are 2 boxers, 1 min pin and one chihuahua. The only one that didn’t get sick was the min pin.

  200. Jennifer says:

    My 1 year old full bred Dobbie “Lynk” has been on Trifexis for a little over 7 months. He is a beautiful, 75 pound energetic puppy who has not experienced any side effects that I am aware of. We also feed him California Natural kibble and have since he was 8 weeks old. I will admit he does not like to take the huge pill but eventually we bribe him enough to get him to eat it. We will continue to use the product as directed and watch for any of the unfortunate side effects others have experienced.

  201. Dee. Dee Rudd says:

    I have used Trifexis on my 2 golden retrievers for about a year. We had a severe flea problem last year. I was giving the dogs interceptor and using Frontline Plus. We would get rid of the fleas for a few weeks then the dogs would get them again. I have never ever had a flea problem prior to last year. One of my friends is a vet and she suggested I try Trifexis. My two Goldens age 5 years old had no issues and never had another flea. I use the Trifexis when the ticks are not out once the ticks start I use the interceptor with Certifect. I am still fortunate I have about 6 months of interceptor left. I am hoping we will be able to get it back soon. We live in a very high tick area nothing works better than the Certifect on ticks. When I put it on the dogs for the first time the ticks started falling off dead within a cople of hours. For some reason the ticks in this area were not getting killed with the FrontlinenPlus. I know a lot of people have not had a great experience with the Trifexis and Certifect. But just like humans many of our Rx’s have a ton of side effects and you just have to do what you think is best for yourself just like your pet. I have had many friends dogs DIE from tick borne diseases and for me it is worth the risk of the topical tick solution.

  202. Cindy says:

    No problems whatsoever for my lab mix. He has a severe flea allergy and topicals have enough of a delay that a single flea can cause serious issues for him. Trifexis kills fleas much quicker, and makes a positive difference.

  203. Erica Brown says:

    Oh my. I am now a nervous wreck! My Boston terrier’s, ages 10 and 7, had their first dose of trifexis today about five and a half hours ago. They seem fine so far but I am scared that I may have given them poison. I took them in for flea treatment because the fleas have been extroidinarilary terrible this year. Everything we have tried has not worked. Our vet highly recommended this medicine, asked about seizure history (none ever with either dog) and explained to give it with a full meal. I can not believe I didn’t research this medicine first! With all of these terrible reviews I would have never given this to my animals.
    There certainly seem to be more bad reviews than good. How has this medicine/poison been allowed to continue on the market? And are there kick backs for recommending this medicine? It seems vets are pushing it hard, refusing to attribute side effects to it and continue to prescribe it.
    I pray my dogs make it through without any of these awful symptoms and I don’t think we will be getting another dose.
    I hope all of your animals who were affected are better now. This website almost certainly screams class action lawsuit to me. I am appalled that this drug is allowed to be prescribed!

  204. joshua says:

    Gave my Newf one dose of Trifexis and within 10 minutes he threw-up his dinner and then just laid around . I will most likely go back to heartgard . Never had issues with it. Just not comfortable giving this. Why risk it if there is a known safe alternative.

  205. samantha says:

    I gave my 3 dogs Trifexis for the first time yesterday. The only who seems to be having adverse reactions its my 6 year old 60 pound beagle/Pitt/lab mix. Since getting her dose she has been breathing funny, twitchy, foaming at the mouth , teeth chattering and vomiting foamy spit. She has never done this before.I can’t afford to take her to the vet and am very worried about her. Does anyone knw what I can do for her at home? I don’t believe she will get this pill again. My other two dogs (1 yr Pitt and a 3.5 yr shepherd mix seem to be just fine.)

  206. Dawn Johnson says:

    I have two Boston Terriers; Lola is 4 and Ali is a little over a year old. Lola has had 3 doses of Trifexis, and Ali just had her second dose. I did not notice any side effects until the October dose. One day after having their most recent dose, both dogs had red splotches on their chests and stomaches. The second day the red splotches turned into full blown welts. Ali, being smaller, has welts covering most of her body. Both girls are eating well and still have plenty of energy. Since there have been no changes in diet, location or animal contact, I only have the Trifexis to question.

  207. Betsy says:

    I decided to try trifexis with my dogs. I have 5. I gave it to them a week and two days ago My puppy, a nine week old great Pyrenees seems to be having trouble with loose stools. He acts fine. My schnauzer mix, Bo, who is 3 years old is itching nonstop. My six year old schnauzer, Brie, has a rash on her tummy, is itching herself crazy, and keeps licking and licking her nose, so much that it has blisters on it now. I just gave her a benedryl. My 5 year old schnauzer and my one year old lab mix seem fine. I have had my six year old schnauzer since she was 12 weeks old. She has never done this before. I really don’t think it is coincidental. I am sure it is fine for some dogs to take, but I won’t be giving more to my dogs.

  208. heather says:

    Our 2 1\2 year old bassett blue heeler mix Miley just had her second dose ofTrifexis her 1st dose the vet said she might notfeel good well that was true kinda sad slow for a couple days. Gve her her 2nd dose month later she was sicke for 3 days vomiting about 15 minutes after she ate acting funnnj she still wanted toeat and drink just would not stay down took her to vet on 3rd day after $312.00 bucks blood work good xrays clearthe vet said probably just gas. well to doses in a row and having MIley feeling THAT lousy we will go back to the old meds that were doing fine. As for the person who said she thinks some of these posts are drug reps from other RX companies well I wish I was telling a tall tale but the facts are the facts. Drug reps dont have to talk down other companies they make plenty without having to go to all that hassle.

  209. Jaclyn says:

    My 1 year old Chihuahua named Booby vomited after receiving a dose of Frontline Plus. Over the course of a month he progressed into so much pain he couldn’t move. He was started on a course of antibiotics and Rimadyl thinking he either had a spinal infection or a herniated disk. He was on a rollercoaster of getting better and the regressing into this immobile and painful state. For two months, I used Frontline Plus and for the next two months I switched to Trifexis, not noticing a pattern until a week ago when he completely lost the use of his back legs and was in so much pain he was struggling for air. He was finally correctly diagnosed with an auto-immune disease, which was why all his joints were swollen and so incredibly painful. I have read that if an animal has an underlying auto immune disease that the use of some types of heart worm prevention can irritate it and turn it into a full blown systemic auto-immune disease, which he now has. Going back through my dates I see that he got worse almost immediately after receiving this medicine, with the last two doses being the worst. He’s on a treatment of steroids but he may need to be put down in a few days if he doesn’t improve. I’m hopeful he can make it for another month or two OFF of heart worm medication to see if he gets better. I hope it’s not too late, he’s still so young.

  210. Jaclyn says:

    My 1 year old Chihuahua named Booby vomited after receiving a dose of Frontline Plus. Over the course of a month he progressed into so much pain he couldn’t move. He was started on a course of antibiotics and Rimadyl thinking he either had a spinal infection or a herniated disk. He was on a rollercoaster of getting better and the regressing into this immobile and painful state. For two months, I used Frontline Plus and for the next two months I switched to Trifexis, not noticing a pattern until a week ago when he completely lost the use of his back legs and was in so much pain he was struggling for air. He was finally correctly diagnosed with an auto-immune disease, which was why all his joints were swollen and so incredibly painful. I have read that if an animal has an underlying auto immune disease that the use of some types of heart worm prevention can irritate it and turn it into a full blown systemic auto-immune disease, which he now has. Going back through my dates I see that he got worse almost immediately after receiving this medicine, with the last two doses being the worst. He’s on a treatment of steroids but he may need to be put down in a few days if he doesn’t improve. I’m hopeful he can make it for another month or two OFF of heart worm medication to see if he gets better. I hope it’s not too late.

  211. Jennifer says:

    3rd Dose of Trifexis with some concerning side effects. We have 1 English Bulldog pup (7 mos old) only adverse reaction was diarrhea, 1 male French Bulldog (3 yrs old) No reaction, and the bad news 1 female French Bulldog (4 years old)-she looks like she is high on drugs, eyes are twitching, body has uncontrollable tremors, she is staring at the ceiling and her eyes are rolling to the back of her head, she can hardly balance herself and is rolling off of her little chair (4 inches off the ground). She has not eaten or drank anything the whole afternoon. This has all started within 6 hours of her dose. After reading other pet owners stories on this site as well as others I’m frightened. I’ve seen some of these pets have some of these symptoms but not all that my Frenchie is experiencing. Please note *she is not on any other medications, vitamins and nothing has been changed in her diet or atmosphere. The only thing she has been given is the Trifexis that she was due for.

  212. Kiera says:

    My vet prescribed Trifexis for my rescue miniature poodle. I did what the maker Elanco said & sent them the package stamp for $10 rebate. Now I can’t return it to the vet because of removing the package stamp and Elanco says they haven’t gotten any reports of problems and because I wasn’t calling to report one they couldn’t do anything. So I am out $125. I was told that I could give my dog the product and then call them back if she had any problems.
    Everyone who has had a problem needs to call them (1-888-545-5973) and let them know.

  213. Tina C says:

    I give my pug Trifexis monthly with a full meal with no problems or side effects whatsoever. She won’t eat it though – have to hide it in peanut butter.
    Drug reactions can occur with ANY heartworm medication or prescription though.

  214. Chris Ralpk says:

    Less than a 2 year old tea-cup Maltese. Started Trifexis
    a week ago. She got diahreha,and took her to the
    Vetrenarian. She lived one day and we lost her. Do not!
    Do not! recommend this product!

  215. Steffany G says:

    I gave my 5 yr. old 70 lb Boxer Trifexis and in less than 3 hours he had a grand mal seizure (no heart beat, not breathing, white gums, tongue was black – not pink, body extended stiffly, dilated pupils, defecated). Thank God it happened in my living room in front of my sister who immediately screamed for me to come running! When I saw he had no pulse and was not breathing I immediately started CPR and was able to resuscitate him after several minutes. I took him home from the vet that night and have been watching over him for the past 22 hrs. He has not had another seizure since that one. He never had a seizure before I gave him this pill. I cannot prove that Trifexis caused the seizure but I will never use it again.

    I had been dosing him with Trifexis monthly for the past 6 months. The last time I gave it to him I had a funny, curious feeling about his behavior but dismissed it as being an overly protective owner as he’s my baby. This time instead of chewing the tablet like he previously did he spit it out instead…I thought he was just being onery. I feel a tremendous since of guilt for hiding it in plain yogurt to trick him into eating it when I should have trusted my dog.

    Ironically, I had told the receptionist at the vets office that I wanted another product that they used sell me before they had recommended this drug. However, she told me that they only sell the other product now for dogs that test heart worm positive so I trusted her and believed her. I should have trusted mine and my dogs instincts. I just hope there is no long term effects.

  216. Vickie r. says:

    This is the second month n trifecta. The first month both of my dogs, brothers, Maltese-shit tzus, vomited but they don’t take the well, we have to force them down . Today, again, they vomited a lot. So we re dosed. One is done ok, the other is lethargic, staring at the ceiling and shivering. I will not be giving them this again.

  217. lucy says:

    I am looking at my mini poodle pomeranian right now trembling, eyes glazed, will not eat or walk and moving his front legs like he wants to go somewhere, but they will not respond. He is 5 yrs old and had his Trifexis yesterday. He has been healthy up to this point . I will be calling vet in a.m.

  218. JANET DORSEY says:

    I want my sentenal back…my dogs …min poodle, 10 & Lhasa apso 11 have been on trifexis for a few months, the poodle has seemed to tolerate the med ok…she is on the 10-20 # dose…weighs 15 #…,but the Lhasa apso vomited to the point of dehydration in June, this was blamed on anything but the trifexis,(was on rimadyl for arthitis…they figured it might be that…a reasonable conclusion…except he had not had a problem with it and was also taking pepcid) … it started on the same day as the trifexis was given (with a meal)… he vomited food and foamy white- yellow/bile..(he was 27.7 #) (large lhasa and slightly overweight ). Well, once again we gave the boy, with his morning meal, the 20 – 50 # dose…with in 2 hours he began to vomit the same as he had previously, but continued to want food and drank water well…he continued to have intermitant small bouts of vomiting, I switched to a more bland home made diet of rice and ground beef as suggested on his prior illness, in 1 week he ended up at the vet, was given cerinia inj for vomiting and he seemed to feel betted, didnot vomit for 2 days and remaikned on small feeding of the rice/beef…then he stopped eating…his weight on 10/9 was 27.7, the first visit to the vet 10/24 he was at 26.5 and by te next week 26#…he again had the inj for vomiting, cbc, electolyte, liver panel tsh, heartworm tests all neg with the exception of a slight raise in the alk p…these tests were compared to the previos labs done in june…and again abd xrays were done…showed normal gas patterns, but a thickened stomach wall, once again the vet did not think it was the trifexis…lpossible a food allergy…? very coincidental…I am afraid to continue this drug and will be returning it to the vet….if nothing else it seems the amt for a 27.7# dog should be much less than for a 50 # dog!!! My boy Sherpa is getting better, thank god…I will be contacting the company and the FDA as suggested! Thanks for this forum, I now have seen where othe poor dogs and owners have had to suffer and my thought that it was the med is not merely my paranoid imagination.

  219. JANET DORSEY says:

    Sorry, forgot to mention the loose stools as another symptom and that Sherpa has been off the rimadyl since the June episode.

  220. CK says:

    I have a 6 lb. Yorkie and just gave him his second dose last night. He had the same reaction as he did with the first dose. He looks like he is on some sort of acid trip. He is lethargic, holds his head at a very awkward angle and stares at the ceiling. We are watching him closely. My other dog is a 30 lb. mixed breed and he doesn’t seem to have any issues. I won’t continue to give this to either of my dogs though. The benefit doesn’t outweigh the potential risk for me.

    1. Amber says:

      Not to be rude, but if your dog had severe side effects like that on the first dose, why would you give the second dose?

  221. Dylan says:

    We have an 8 month old, 37lb. mix breed. She was labeled as border collie when we rescued her but we think she has a lot of flat-coat retriever in her.

    She took her first does of Trifexis last night and within an hour, her lips had swollen to the size of sausages and felt like rocks. She was obviously in quite a bit of discomfort.

    We had to go to the emergency vet for an injection of benadryl and then, later, a steroid injection. Followed up by 3 doses of benadryl at home today. We can’t definitively say it was the Trifexis as she spent some time outside in our yard by herself (could have been bit or stung by something) before getting the treatment but it seems pretty suspect that the Trifexis was the only newly introduced thing that day. The emergency vet was able to guess, by name, what heartworm pill she had taken without me telling them on the phone so they obviously have seen this issue before. She definitely will not be getting it again…

  222. Brooke says:

    Thank you so much for this. I found this article last night at 3:30 am while in the ER with my 11-yr old German Shephard mix. 8 hours after his first-ever dose of Trifexis, he started shaking like he was cold. He was lethargic, legs collapsed under his weight when he tried to walk, drooping eyelids, everything that the others here have described. Vet wanted to refer me to a neurologist before I saw this. We are now at about 12 hours after Trifexis, and he is doing much better. Just had breakfast, we’ll see if he keeps it down. My other dog, 6-yr old Whippet mix, just isn’t himself today, not the bouncing ball of frenetic energy that is his normal, but not nearly the severity of the symptoms as my GSD. If anyone from Eli Lilly is reading this, you owe me $400 for my ER visit. I’ll also be returning the rest of my Trifexis, because I do not wish to POISON my dogs again. Thank you again so, so much to everyone who posted here.

    1. Cassandra says:

      Our dachuands were switched to Trifexis this past week. They both took them fine. After 4 days my little girl was swollen almost twice her size. She tucked her tail and pulled up her back legs. We took them out to do their biz and she just stood their and stared at us. We brought her back in and I had taken to my bed so I could watch her behavior closer. She looked upward, smacked her jaws and was definitley having a seizure. My other dog has seizures and is on two meds 2x day. He has them so severely that he ruptured a disk in lower back and had to have surgery/rehab for 3 weeks in hosp. and 3 months at home before he started acting normal again. He still splays legs, has hump in back, cannot run or naigate terrain. It should of never been given this med. My vet knows this and has taken care of all my animals for over 20 years. My little girl began shaking and came straight to me with theses huge eyes, she was so scared and she is a “daddy’s girl” and only comes to me for needs. My dogs do not need flea control either, we have never seen a flea on any of them nor seen them in house. We have treated them though if we have been to a hotel where dogs are welcome just in case there are fleas/eggs present. These are her symptoms: bright red ears, she is freckled and white, her belly was re. lethargic, confusion, temors and twitching,pain when picked up, she would cry like a little baby, swollen all over, almost like her coat was inflammed. Unsteady on legs, especially back ones, kept her tail tucked up. She would not leave my side all night , she slept on a pillow next to me all night with her legs kicking me on occasions in her sleep, she would be hot then feel cold. This is what I did for her after I called the vet and he said could not be the pill after 4 days. (I don’t think that’s true). I gave her 1/2 of benedryl tablet, 1 ACE pill, it’s a sedative we give them if we travel, kept her next to me, kept her covered with blanket even if felt hot. I think she had a fever. We stayed like this all night and most of next morning. She gradually pulled out of it. I was hysterical as these are my babies and I don’t understand why this drug is still being given. I asked the vet if they had other people calling about Trifexis and they said yes. So who does that?? If one person called, I would pull that med, investigate it . There were other options right on his shelf. Like I said my other dog should of never had this in first place. Now am watching both very closely for any signs of side effects. Neither of my dogs vomited or had diareaha. My advice to everyone out there, DO NOT KEEP GIVING YOUR ANIMAL A DRUG THAT HAS MADE HIM SICK EVER AGAIN. I read so many of these stories of the first time, then the second time and on the third. STOP IT AT ONCE, NO DRUG THAT CAUSES THIS MANY PROBLEMS AND DEATH IS WORTH IT. There are other meds out there. Question everything, Vets are like doctors, science is not exact only trial and error. Do not let them tell you it is not this drug when your pet has never behaved this way or is now dead!!! We know our animals, they only treat them. They all know this is a bad drug!!!!!!!!!!!!!!!!!!! Hope no one gives this to their pet ever again. As for those few that haven’t had any problems, you are very lucky. And as for the women that said we are haters for leaving these comments, you are crazy, if your pet became ill you’d jump the fence. We are not haters, only lover of our animals.

  223. Montra says:

    Our 1 year lab died this week, I believe because of Trifexis. She was a perfectly healthy happy dog before starting Trifexis. She was switched from Sentinel to Trifexis three months ago due to the Sentinel shortage. After the first dose, she began becoming weaker and having trembling in her legs. The second month, she began vomiting, having diarrhea, losing incredible amounts of weight, no appetite, drooling, scaly skin, losing fur, and continued to get weaker. After the third monthly dose, she was so lethargic and weak, she could barely walk. She was skin and bones by this time. The vet didn’t find any obvious cause of the symptoms. I didn’t make the connection between the Trifexis and her symptoms until it was too late. She died of liver failure this week. We are heartbroken beyond words. Please do NOT give this drug to your dogs.

    1. Tammy Mann says:

      I’m sorry Montra. I’ll never use this product again!

  224. ruth newsome says:

    I have had at least 3 problems with Trifexis – 1 – I gave it to my 10 wk old puppies on the advice of my vet because he said comfortis was not available and this was the same except it had worm meds added. My puppies (14) all had a terrible itching problem that did not go away for weeks 2 – I gave it to my old collie (13) she was fine acting normal able to do the 5 steps on the back of the house after giving her trifexis she lost the use of her back legs and had neurological problems turning in circles constantly. 3 – I gave it to y collie about one month before she became pregnant – the puppies were all born small and deformed some grossly so. This product needs to be recalled. the manufacturer sued

  225. Dusty says:

    Gave our jack russal trifexis yesterday. Last night she started vomiting foam, has bloody diaria, tremers, stomach drawn up, won’t eat, and just plain sick. It is now the next night and she is no better. There will never be a second dose.

  226. Jane says:

    I have a 9 year old cocker. Several days after her first trifexis dose she had a full grand mal seizure. The only change she’d had at all–food, environment, anything–was starting her on Trifexis. I took her to the emergency vet that evening and she’s otherwise healthy–blood tests all came back normal, good blood pressure, everything looks fine. She’s had two far milder seizures since. When I called my vet the next morning, he said Trifexis is contraindicated for dogs who have a history of seizures, but she’d never had any prior to the first dose. I have not given her any further doses of it. I was shocked to read everything here. Thank you for letting folks know about this.

  227. Wes says:

    I gave my 3 year old Akita Trifexis at the recommendation of the Vet & I didn’t notice symptoms until after the 2nd dose. Now his legs are swollen and his skin is red all over his body. He has bumps on his head and red open sores in side his ears. Went back to the vet and got Steroid shots & water pills as a treatment but a few days later the swelling has gone down but the redness is worse. He has been wearing the cone so he is unable to bite at the sores but they are still oozing blood. Going back to the vet today to see if there is anything we can give him to make him comfortable.

  228. Tammy Mann says:

    My dog, Sophie, is a one year old shi tzu. I gave her trifexis as recommended at vet’s office. She starting acting strangely. Sleepy, head back, eyes rolling back, she has lost her balance. She slept with me and continued with labored breathing not getting comfort. She is really scaring me because she will not drink. A full day later she is walking some. She isn’t herself and still won’t eat or drink but is recognizing familiar words again.

  229. Richard says:

    In my opinion, Trifexis is dangerous and should be banned. I have 2 dogs and they both had their third and last dose of this drug. One dog who is a young border collie/lab mix appeared ok, but with our other dog, a chow/husky mix, after the second dose, I did notice he was lethargic and had diahorrea and was vomiting. I didn’t connect it with the Trifexis that time, but after I gave him the third dose this month, I thought it was the end for him. He was lethargic, wanted to sleep all the time, was vomiting, had diahorrea, labored breathing, and had difficulty standing up. When he did get up he walked a few steps and then his back legs just gave way under him. It would seem that the symptoms get worse the more doses the dog gets. Please, if you are researching Trifexis as an alternative to Sentinel, or any other flea/heart worm treatment ….. DO NOT USE IT!!!

  230. Lauren says:

    Ok, well, I’m glad AND terrified that I found this. I just gave this to my two dogs yesterday (6lb toy poodle, 13lb toy poodle) and things aren’t going well, so I decided to google it. Louie (13lbs) vomited this morning and it had little bits of blood in it. He’s not wanting to play or bark at dogs, just wants me. And then there’s Olive (6lbs)… She seems completely dazed. She couldn’t jump up to me on the sofa (tried and failed), is walking around like she’s lost, her eyes are all crazy, and she’s tremoring. We just plopped down $2k on a car repair and have no money to take them to the vet.. I’m so scared for her, and I feel like such an awful mom for not looking into this before giving it to them. I will NEVER give this product to my dogs again.

  231. Eric Feldmeier says:

    I lost my dog to trifexis and my heart is broken, we rescued her 3 years ago from a bad owner and my wife and I (and our pug) fell in love with her but our time with her was cut short by a Trifexis.  We worked as hard as we could to comfort her and help her come out of her illness from the med almost losing our jobs to stay home and care for her all to watch her deteriorate and finally die. Please read and post any part of my French Bulldog’s story.
    On July 5th 2012we gave our 5 year old French BulldogMadeline Trifexis after two failed attempts in the months prior where she spit out or vomited out the pill- I wish we would have listen to her message.  That same day she had a seizure foaming at the mouth and convulsing so we took her to the vet at which time he gave her an anti-seizure med and said it was likely a reaction to Trifexis. We immediately reported this to Trifexis and their Vet Dr. Watts was kept up to date on her status and paid for some of her vet visits.  For the next month she would not eat or drink and was wobbily and lethargic.  After a month and some slight improvement our vet began to taper her off of her anti-seizure medication.  A few days later she had 4 seizures in a 24 hour period.  This was reported to Trifexis at which time they assigned us to a Neurologist in our area who was quick to defend Trifexis.  Over the course of the next two long agonizing months, Madeline had more seizures, has to be fed and water with a dropper and generally got worse and worse, wandering amelessly seemingly blind.  Finally in September after a seizure that left her with two different size pupils which was a sign of brain injury.  After an attempt to treat her with steroids, our vet and the neurologist suggested we put her down. 

    Our dog had suffered for 3 months with seizures, no appetite and possible blindness before she ultimately had to be put to sleep.  The Trifexis vet Dr. Watts said that the med “likely uncovered a pre-existing condition” and likened it to a allergy to peanuts which was an insulting analogy.  Our dog was happy and healthy and never showed any signs of brain injury or seizures.  Before this incident she was 26lbs, she died at about 15 lbs, a shell of her former self.
    Don’t give your dog Trifexis, with all of the similar stories of seizures and death it is not worth the risk when there are other meds out there.

  232. Christina Fox says:

    On July 5th we gave our 5 year old French BulldogMadeline Trifexis. That same day she had a seizure foaming at the mouth and convulsing so we took her to the vet at which time he gave her an anti-seizure med and said it was likely a reaction to Trifexis.

    We immediately reported this to Trifexis and their Vet was kept up to date on her status and paid for some of her vet visits. For the next month she would not eat or drink and was wobbily and lethargic.

    The next month she had 4 seizures in a 24 hour period. Over the course of the next two long agonizing months, Madeline had more seizures, had to be fed and water with a dropper and generally got worse and worse, wandering amelessly seemingly blind. Finally in September she had a seizure that left her with two different size pupils which was a sign of brain injury. After an attempt to treat her with steroids, our vet and the neurologist suggested we put her down.

    Our dog had suffered for 3 months with seizures, no appetite and possible blindness before she ultimately had to be put to sleep.
    By the time we had her put down, she was only 16lbs, 10lbs lighter than her regular weight.

    As for your “gut feeling” I wish you could have spent just one day with my dog before, then after she took this pill. My “gut” has been feeiling terrible since this happened. Fact-Trifexis works on fleas and ticks by making them have seizures until they die. Fact-A lot of dogs who never had seizures have had seizures until they die.

    Do not give your dogs this drug (or for you vets, do not perscribe it.

  233. Sarah says:

    I was given a Trifexis sample at my veterinarian’s office for my 16 week old Jack Russell mix. My veternarian said he is prescribing Trifexis in his office for the superior flea control. Fleas in Texas have built up an immunity to Frontline and Advantage. My veterinarian told me to feed my puppy before administering Trifexis to avoid an upset stomach. I fed her dinner, administered the Trifexis (which she readily ate with no coaxing), and we have not experienced any symptoms. She was crazy playful the next morning. No lethargy, no vomiting, no diarrhea, no symptoms at all. I will definitley be purchasing a six month supply on our next visit.

  234. Amber says:

    I have a 2 year old West Highland Terrior named Charlie. After doing alot of research, I decided to try Trifexis. I love that it treats heartworms and fleas all in one small, beef flavored tab! I have had NO issues what-so-ever with this product and actually LOVE it. If you look at it like this it may make some sense to those that have animals who were effected by the product; dog medication, just like human medication does have side effects (some mild and some serious.) I could take a medication right now and have no side effects at all and some one else take the same meds and have various side effects. I am sorry for all of you whose pets have been negatively effected by this medication, but just because your certain breed or particular animal experienced these side effects does not make it a bad medication. I would recommend this product to anyone looking to get heartworm and flea prevention all in one.

  235. Frank says:

    Dog: 75 lb mix
    Symptoms two days after Trifexis: vomiting, will not eat, drinks minimal water. Lethargic, bad defication (liquid), dog is not acting normal. No other medications. Started researching Trifexis; similar side effects on other peoples’ dogs. No more Trefexis. Thank everyone for their posts about their positive and negative reactions with Trifexis.

  236. J. Suton says:

    I have just purchased Trifexis for my poodle. she has been on Advantage and we cannot get rid of the fleas on her. I am very allergic to the fleas. I have used flea bombs , sprayed chemicals, vacuumed the house every other day, lifted the carpets up of the hardwood floors and nothing is working. We can’t see the fleas only black specks. They seem to be biting her and myself at night time. Please give me advise on what to do?

  237. Arisa Toy-Ballentine says:

    Breed: English Bulldog
    Age: Just turned 1 year old on 11/17/12
    Side effects: vomiting, disorientation, 3 minute grand mal seizure.
    How long after administration of Trifexis: Vomiting started a few hours after. Disorientation started about 12 hours after dose. Noted seizure less than 24 hours after dose.
    This was Winston’s first dose of Trifexis and we have never seen any neuro problems in him before yesterday. He is seeing a vet today for followup. I reported the adverse reaction immediately afterwards. I will be requesting my money back on the remaining 5 doses and be very vocal about what we have experienced.

  238. Victoria says:

    The dog I give the Trifexis to is a Border Collie, approximately 4 years old. I really hadn’t noticed anything much right after giving her the medication, but I have noticed that since I started using it, she is always itchy and sometimes her ears seem irritated. Is it the medication? I don’t know. I may try stopping it for a couple of months, then resuming it and see if there’s a difference. She is not a really high energy dog, unlike most Border Collies, but I will pay attention if and when I give her another dose and see if she seems more lethargic or anything.

  239. Lisa says:

    I can’t tell if I am typing this in the right area, but hopefully I am. I have a Shiba Inu who will be 1 year old 12/11/12. I got him when he was about 5 months old, so has been with us 6 months. He has always had what I consider pretty loose stool from soft serve to puddingish, but always on a pretty regular schedule. The fecal samples from the vet have been negative for parasites, but due to the difficulty sometimes in tests detecting them we did a 2 week treatment (metro something). We also have just completed a 3-day panacur treatment, again trying to eliminate any possible parasite issue being the cause. We have also tried several different high quality non-grain foods, but not yet a full elimination type diet. When we first got him it was my understanding softer poo in pups is not unusual so we weren’t too concerned, as the months go on we are now concerned and looking for answers. As I read more on Trifexis I am wondering if this could be a cause? Problem is with so many possible causes of soft loose poo and no solution yet, we don’t know, but after reading a lot of internet posts I think I will be discussing with my vet alternatives here in South Florida to Trifexis to see if there is a change in his constant never ending soft poo issue.

    1. Lisa says:

      I should add, until I eliminate Trifexis I won’t know for sure it is the cause as since we had him he has been on it. It is the one constant (other than possibly cheese) though during these past 6-7 months.

    2. DrMarie says:

      Lisa, to ask a question, you’ll need to use one of the question options here.

    3. Bob says:

      Lisa try. Feeding your dog origen, it is a grain free dog. My goldens have the best stools and healthy coats and your feed less amount due to very very high quality product. May need to feed half of other dog foods. Good luck

  240. Belinda says:

    I have a six-year-old rescue dog–a 63 pound Shepherd mix. I gave her Trifexis on Monday morning and she barfed up her breakfast and her dinner (I didn’t discover the breakfast barf until after I gave her dinner and she barfed that up). I have a dog walker who comes around noon so I left a note for her so she can let me know if Josie barfed again today (Tuesday), and she did. I called the vet and he said to give her a bland diet for a day or two and to give her pepcid AC. I will NEVER give my beautiful girl that nasty poison again. When I opened the little pod where the dose was, it smelled like some kind of poison or mothballs. I should have gone with my instincts and not given her that horrible stuff.

  241. Lorie says:

    I gave my Jack Russell Trifexis, the proper dosage for her 14 lbs weight. Within 1 hour she threw up and then began shaking and was very off balance, she looked drunk. When we went outside she kept looking up at the sky and then losing her balance, like maybe she saw the stars and they seemed to be moving (?) I called the company and they said if she got any worse to take her to an emergency clinic but that the effects should wear off. They did lessen but she hasn’t been the same since. She often loses her balance and will actually fall over at times for no reason. It’s like it caused neurological damage, it’s really irritating. Of course they will never admit something like that, but it’s really sad, she’s not the same dog at all. She seems to be losing the control of her back legs, one especially, and before that night she was extremely healthy and active, an everyday ball player. It was the first time we had ever used it, and won’t ever again of course.

  242. Cindi says:

    I have a 8 year old lab mix and a 4 year old German shepherd mix and they have been taking Trifexis for 3 months. The lab did not seem to have any problem with it until the last dose. He became a little nauseated. The shepherd, on the other hand, became nauseated after every dose. I gave him a pepcid ac with each one.

    I was nervous giving them the dose each time because of the nausea and after reading these comments, I will be going back to the topical treatment and Heartguard.

  243. Librarienne says:

    Our dog, Buddy, a 11-year-old pointer mix that weighs 62 pounds, was switched to Trifexis at the recommendation of our vet because of a case of fleas. They gave us the dosage for 60-100 lb. dogs. He threw up the first one and we redosed, and then he spent the rest of the day kind of out of it and sleepy. The second month he ate it just fine and was again lethargic that day. He also began having some other issues that I hadn’t attributed to Trifexis until reading this. The day after his dose, he was excessively drooly, shaky and irritable, he’s had some issues with his balance, and he’s started having trouble with his back legs giving out on him, like they are too weak to hold him up. We thought he was developing age-related problems, and our vet supported that idea, but now I am thinking it was the Trifexis. We won’t be continuing him on it.

  244. Wendie says:

    I gave my 14 week old Doberman Trifexis this morning. She had her 3rd set of shots yesterday & the vet suggested Trifexis for fleas. I had never heard of this & so I didn’t think it was something that could harm her. But she has gotten more lethargic throughout the day. At first I thought it was from getting her shots, but decided to check the side effects on Trifexis online & in the pamphlet the vet gave me.

    I feel horrible that I didn’t research this stuff prior to giving it to my puppy. I am praying that she will be back to normal in the morning. Right now she seems uncomfortable, like she possibly has a stomach ache & she just isn’t acting like herself. She wasn’t playful at all this evening, although she did eat and drink. One thing that I haven’t seen mentioned in the comments was anything regarding worms. I was aware when she went to the vet that she had tapeworms, and after she received her dose of Trifexis, within 3 hours she began have large amounts of dead worm pieces expel from her behind. It is quite disgusting. I don’t know if this is normal or not. I have a completely different med that I’m supposed to give her next week for the worms, but I don’t think I will give her that or Trifexis again.

    My vet never mentioned any adverse affects from this med & that really upsets me. I know as a puppy parent I should have asked more questions about it though.

  245. Jason says:

    I have a 2yo male mini schnauzer and a whole Trifexis dose will cause him to vomit about 2-3 hours later. I divided the pill for an am and a pm dose and he seems to tolerate it but he will be very sleepy, glassy eyed, and act drunk. It usually wears off by the end of the day, or the next morning.

  246. Cheryl says:

    I have had my Cocker Spaniel male on Trifexis since his first vet visit in 2011. I follow the directions and make sure he eats all of his food before I give him the pill, which he sees as a treat for some reason and chews that little puppy right up. I don’t give him the pill every month, it’s usually a month and a half apart or even longer. No side effects so far (very happy dog, jumps up when he sees you, no loss of appetite, and only whines when you walk out the door and he can’t see you anymore). This year, when flea season hit us hard, I noticed his itching didn’t go away after giving him his dose of Trifexis; fleas are gone but he’s still itching like crazy (which if Cocker’s have a full skirt is a terrible mess). This year, about 4 months before giving him the first dose of Trifexis, I switched his dog food and have been religious in getting this particular dog food. His vet was worried that Trifexis might be why he’s still itching when I took him in for his check up and shots a couple weeks after the first dose. I will be changing his dog food in a few days and we will see if it’s the dog food (as I suspect) or the Trifexis. But I will be continuing to use the Trifexis until we discover what is causing the itching or until he shows any other side effects.

  247. Genesis says:

    I have a Maltese-Yorkie mix, and as soon as he started weighing about 10lbs (maybe since June/July) his vet switched him to Trifexis from Revolution. The first time I gave it to him, he loved it!! I made sure, and still do, to give him a full meal before I hand him his Trifexis ‘treat’. He has never had any side effects to Trifexis and I am happy that I can give him all the protection he needs in just one pill!! Living in Florida, that has been a great help! From time to time, I’ll notice maybe one or two fleas, but they never actually bite him, and those that do, fall off a little afterwards. He has gotten his last puppy shots and will be turning 1 in January. All I can say is a big, awesome ‘THANK YOU!!!!!’ to the makers of Trifexis for helping me make sure my Ace is as healthy and happy as he should be in his puppy-hood!!

  248. Mark says:

    Our 2 year old mixed boxer, red bone coonhound and 10 year old welsh terrier have been on Trifexis for more than a year. Neither have had any side effects from the medication — at least that we have seen. They are both inside dogs and I’m around them almost full-time. I would probably have noticed had they suffered any side effects.

  249. Wild Dingo says:

    I gave it to two dogs. A 5 year old Siberian Husky and a 5 year old GSD-Formosan Mt. Dog mix. The GSD mix had a reaction within 4 hours. Neurologically based, tho he looked liked he was going to throw up at one point (he never did). He staggered, stumbled, paced and looked scared out of his mind. I wrote a story on my web site about it specifically and linked to your site as well.

    I intend to call the 800# on the box and report it.

  250. Michelle says:

    Gave my 2 year old black lab Trifexis 7 hours ago. He is having siesures, is trembling, lethargic, glassy-eyed, amd won’t leave my side. He is also periodically exhibiting odd yawning-like behavior that looks like he is chocking or mabe ready to vomit. He has no history of siesures, and was perfectly fine before I gave him the dose. I will be calling my vet as soon as they open and will never use this again.

  251. chris gray says:

    6 months ago i had “the perfect lab” according to our vet. that day we started trifexis. on Thanksgiving day i gave 2 and 1/2 year old Molly her 6th dose. That Sunday she became very lethargic, and started vomiting horribly. The next day xrays showed a blockage in the stomach allowing passage through. Our vet assumed she ingested something and was unable to pass it and recommended we go to the emergency vet for surgery that night. at 330 am i received a call saying that what in fact the problem was that there was a large mass blocking passage from her stomach to intestines. The emergency vet said it was “beyond her level of expertise” but probably cancer and untreatable. We made the decision to put her down. I called Trifexis the next day and they offered to pay for a necropsy to see the cause of death. I spoke with one of their resident vets and she was very nice and thanked me for contacting them and letting them run the tests. the fastest way you can help others if there is a problem is to notify them! i should know the results in another week, ill post the results.

    1. chris gray says:

      We got Molly’s necropsy results back today.

      Severe necrosis of the stomach, intestines, and pancreas which caused severe internal bleeding and hemorrhaging.

      “basically her organs were melting inside her”

      “we are not sure of the cause but cannot conclusively deduct that trifexis was to blame but the FDA will be looking into it”

      She was 2 1/2.

      I think that in a year or so trifexis will be pulled off the shelf and a civil action lawsuit will happen and ill get a check for $25, which i will promptly wipe my butt with.

  252. Dawn Clark says:

    I have 2 rottie’ mixes, a German shorthair & a Rottweiler. This is the second time I have given trifexis to them. The rotties are all lethargic & act dazed. My German shorthair seems okay. She is the oldest of the four dogs. I won’t be giving them trifexis again, I can’t get interceptor so guess I will go back to heartgard.

  253. Helen Dodge says:

    My 1.4 year old great pyrenees went in for his physical and my vet was out of Sentinel (which he had been on for the last year) and prescribed Trifexis. 1 hour after giving Winston his dose, he started panting heavily and drooling more. His ears and the pads of his paws became red and hotter than normal. He has lost his appetite for the last 3 days and has had constant diarrhea. I will never use this product again. I feel like I’ve poisoned my best friend. His breath hasn’t been that of my puppy, but a toxic scent and when I kissed his ear I got a metallic toxic taste in my mouth. I called my vet the very next day and told them of the side effects and was told to give it a few day and we’ll go to heart guard and frontline. This product should be reevaluated or taken off the market for further testing.

    1. Helen Dodge says:

      Winston had his first solid poop today and it took 23 days with lots of rice and pumpkin mixed in his food. His energy has finally returned, but still dealing with the dry skin from the patchy rash that flared up after the dose. My vet has since been replaced and Winston will get Heartguard and Frontline until Sentinel is back on the market.

  254. Sunova says:

    I have a female German Shepherd Puppy, Sunova, who I started on Trifexis at 6 months because it was recommended by my vet and a close friend of mine who works will animals. I haven’t had any issues whatsoever with Trifexis. Sunova has been on Trifexis monthly for the last 5 months and is as healthy as can be. She hasn’t vomited or acted weird or sick at all after taking the Trifexis.

    She’s always so full of energy, is growing and gaining weight as any healthy GSD would and is always happy and healthy.

    She has a trip to the vet next month to get a check up at 1 year and I’ll see what the vet says on her progress and well being! But, like I said, I have had absolutely zero problems with Trifexis and my GSD has been on it for the last 5 months.

    Hope this helps!


  255. Erin says:

    Trifexis should be exposed. My dog is now in the hospital for the same symptoms listed above. This company needs to recall this medication and all dog lovers and owners alike should know the truth about this medication. My Maltipoo has experienced lethargy, loss of appetite, shaking (fluctuating between shivers and violent shaking), it’s like he is having an out of body experience. He is tired, has loss of balance. I am so upset that the FDA would allow this medication to be on the market after story upon story is released about these negative and sometimes severe side effects. My vet has stopped selling it since Charlie fell sick, he has notified his rep, he has reported the company to the FDA, I have asked to be sent paperwork from the FDA, he has reported the incident to the company as well. I am distraught and upset to say the least.

  256. Jessica says:

    My 2 yr old pitbull/boxer mix has been on trifexis for 4 months, no ill side effects until today, his 4th dose. I’m still not sure if thats the cause but at 8pm we gave him his dose with some food. Then I woke up at 5am this morning because he had vomited and was licking his lips super loud. I cleaned it up, took him out so he could pee, then we came in and I went to pet him and he cowered away and yelped. His eyes seemed like they couldn’t focus, maybe even blind, but eventually he was following our fingers and movement and seemed to be better. Now all day he’s been back and forth between curling up with us and then acting anxious and cowering in his crate. With no changes from us. We’ve never abused him, we’ve been his only owners, and I can’t think of any other explanation. No changes in soaps or deordorants, no changes in diet other than giving him the Trifexis. I believe he may have had a seizure? If the behavior keeps up tomorrow we’re taking him in, but other than behavior he has been normal. Eating food, drinking water, regular peeing and bowel movements.

  257. Linda says:

    Anyone know if the Interceptor or Sentinel will be available in the new year? I am worried that there is going to be a bad infestation of ticks and fleas in the spring due to a mild winter again. Ugh…..

    1. DrMarie says:

      Just a note: Sentinel is not labelled for ticks.

  258. alice says:

    Had my blue merle aussie since he was 8 weeks old; our vet recommended Trifexis at his first visit. A few hours after his first dose along with his breakfast, he threw up his food which looked undigested (soggy dog kibble), but I noticed no sign of an undigested pill nor any chemically smells. I immediately called the vet, and was told that he did not need another dose and next month I should split the pill in half and give it to him with his breakfast and dinner. Other than the vomiting, he was his usual self, very bouncy, energetic and playful, with a raging appetite, so I figured he must have just had a bad reaction for taking the whole pill at once at such a young age. The next few months I gave his Trifexis pills in halves and he never had a problem. As he grew older and got bigger, I began to give him Trifexis as a whole pill and he is perfectly fine. He is now 1 year and 2 months old with no fleas/ticks ever and passed his heartworm test with flying colors. In fact, I just gave him his monthly dose an hour ago, and I’m having a hard time keeping him from tearing up his new Christmas toy while stomping all over the living room!

    I wish Trifexis was the perfect all in one med for everybody but unfortunately, nothing in the world ever works that way…just wanted to share my positive experience with this medication.

  259. PDS says:

    Hi, I appreciate everyone’s comments and I hope they are all legit… Fwiw, I’m against ALL pesticide’s in or on my dog but the practical reality is that she needs worm/flea/tick protection. We started out 4yr old Dalmation on Trifexis shortly after it came out and have nothing but great results. Our Dal had reactions to anything topical, we tried them all.

    So far, the only downside to Trifexis was a) getting out Vet to carry it and b) it doesn’t completely stop ticks (so we check her).

    No of course our dog has other problems and who’s to say Trifexis has helped or hindered, but so far nothing to directly attribute to Trifexis. Again, no matter what you use, DOSE PROPERLY. It’s way to easy for people to give their dog too much medicine. Luckily my dog is right at 60lb and we use the 40-60lb dose.

    And there’s always new products coming out, keep trying them until you find what works for your dog!

  260. Ronald Knotts says:

    My nine year old male Sheltie has been on Trifexis for three months. About two months ago, I noticed that his skin looked like it was burned under all four legs, lesions that were seeping. He has been on a spray anti-inflammatory and medicated shampoo to heal the wounds. So far they are still there, but somewhat less. One of the more serious wounds smelled like rotted flesh. A Sheltie breeder friend said she has heard a lot of comments from other breeders that Trifexis causes this reaction in this particular breed. Asked my Vet and he said he was going to research it further. My Sheltie is due another dose. I am NOT going to give it to him. I am moving him to Iverhart Plus and K9 Advantix tomorrow.

  261. lynda C says:

    My 8 year old Pom has been on Trifexis (mainly for fleas) for over 6 months. After trying several other flea remedies, my vet recommended Trifexis and it’s worked great. No side effects whatsoever.

  262. WestieLove says:

    I have two Westies. 3 and 11. They have received Trifexis for over a year and not a single issue. I would recommend Trifexis. Unless something else is cheaper I will stick with Trifexis.

  263. salli says:

    Anyone who continues to use this, please be sure to run liver chem panels on your darling. Also Thyroid panels. This reversal of drug induced Pancreatitis is very difficult, and worse for those whose pets have died. I am lucky I still have my dog, but she sure isn’t out of the woods. If they don’t have a seizure, (which is the side effect most vets are looking for) This can seem like random bouts of digestion issues. Easy to say it is just something they ate or bad food. Once the damage is done, and Trifexis is out of their systems again easy to write off as something odd food, grass, virus etc. You dont want to end up with death! Please please be careful. Devastated here…

    1. michelle says:

      I had a standard poodle puppy, he died at 12 weeks old. I took him to the vet right after I got him at 8 weeks. he was healthy and eating well. He did have fleas so the vet recomended trifexis. He started developing symptoms of lethargy, disorientation, and not eating well about a couple of days after giving trifexis. I took him to the vet on the 2nd day of these symptoms. The vet gave him fluid under the skin and said if he wasn’t improved by morning to bring him back. In the morning he was worse, I took him back. He died 3days later. Liver had shut down etc… I racked my brain trying to figure out why. The vet never asked about the trifexis or indicated that there perhaps was a cooralation. I am thinking now, there might have been. I did get another standard puppy from the same litter and have had him on trifexis with no problems. My small mix breed has also been on it with no problems. After reading more about the med, I am hesitant to give their dose this month. I really don’t know what to do as I don’t know for certain and neither does the vet, what my other puppy died from.

  264. Eric Feldmeier says:

    For the multiple bad experiences posted on here, there is an additional way to make your best friend’s loss worthwhile:

    Fill out this FDA form that outlines your adverse event and let’s all work together to get this drug off of the market:

    It’s a few pages but if all of us who have lost or have had our dogs suffer fill this out, we can actually avenge our beloved companions.

    Please fill this form out, be honest and include any vet info and diagnosis that you can. If the stories here are just 25% of the dogs that have died, there must be hundreds if not thousands more that go unreported online

  265. Jode says:

    We are experiencing the same side affects as the affected dog in your article. We have administered a total of 4 45-60 pound doses with no side effects. The problems started each time we gave him the higher dose of 60 and up dose. The last 2 doses have resulted in panting, confusion, unsettled, walking abnormal and more. We will not continue with this product.

    1. Erica Levine says:

      My dog also had the same side effects as your dog. He is 91 pounds.

  266. sunny says:

    I currently have two dogs — I switched to Trifexis for the first time because we wanted oral form. I purchased Trifexis from our vet and gave to our dogs last night with dinner. This am, one of my dog, ~65 lbs, is much less active, has swollen face, esp eyes, has fine tremors. Gums don’t appeared to be swollen, no breathing or swallowing difficulties and ate breakfast. I do believe this is an allergic reaction. I will be watching him closely for the next couple of days. I will call the vet and the company as well. I will change back to what I have used safely for the past 13 years –K 9 adventix and heartguard plus.

  267. sunny says:

    And I forgot to mention that our ~ 65 lb dog acts dazed, can’t seem to focus as well. He is a rescue mixed breed — hound, lab, boxer – who knows, but we love him dearly. Hopefully he will be better soon. Our other rescue dog, chow/sheltie, 40 lbs mix is just fine. Nonetheless, I won’t be giving either of them, realizing the potential side effects. I will just go back to previous treatments – inconvenient for us but they’ve been around and used for a long time w/o major issues.

  268. Nicholas B says:

    I have a 1 year old Cane Corso. I’ve had her for about 4 months. I took her to the vet for her 1st round of shots and was given Heartguard which didn’t cause any problems. I only got the one dose because I was coming back in about a month for her second round of shots. I was told about the Trifexis at this visit and haven’t had any problems with it whatsoever 3 doses later. My girl is right at about 80 lbs so I give her the 60-100 lbs doseage. I usually break it up and mix it in with a spoon of peanut butter as she doesn’t seem to like it by itself. I don’t know if they offer Trifexis in a chewable or not but the pill I use is hard and not chewable. Do they make it 2 different ways?

  269. Arlene says:

    Gave my dog Trifexis for first time. He would not take it. Smashed it up and put it in his food spiked with low sodium chicken breast and cheese. Still would not eat it. Force fed him the Trifexis. Within 15 minutes he vomited. My dog is a retired explosive detector. He has sniffed out airports and courthouses to make them safe for us. He has even sniffed out an arena for our President Obama. He does not deserve to be used as an experiment. Trifexis is VERY expensive. Too expensive to be vomited up and too expensive to be harming my friend. What are safe alternatives please?

  270. Buffy says:

    I have 4 dogs on Trifexis for 3 months now. I love it!! My biggest dog Salsa was having allergies to fleas and her skin and coat were in horrible condition. After a month of prednisone to combat her allergy and starting Trifexis she no longer has issues. My dogs aren’t itching constantly and their coats and skin are healthier. I had tried frontline and advantage but had horrible results, I guess we had industrial strength fleas. But Trifexis has been wonderful. Nothing but great results!

  271. Diana Steinberg says:

    We just had a second dog die within 3 months, both were switched over to Trifexis about 1 year ago. The older one was 12, diagnosed with kidney failure 2 1/2 months ago and died within 2 weeks. The second one was the daughter of the first, only 10. She started throwing up right after having Trifexis pushed down her throat 10 days ago. (our dogs would not chew it). After 3 visits to the vet she was diagnosed with kidney failure 2 days ago and despite IVs etc. died last night. It’s occurred to us it might be the Trifexis since nothing else has changed in their diet or environment. We are heartbroken, and hate to think this is happening to other people’s dogs too!

  272. bonnie albury says:

    i have an almost 6 mon. old minature australian shepherd.
    he weighs 27 pounds. i gave him his first trifexis on the 19th
    december. he seemed to be fine all that day. the next day
    he only went to the potty to do number 2 once. then on the
    21st, he woke up with diarrea. he still has it and today is the
    22nd. i am having a feeling that this is coming from the
    trifexis that i gave him on the 19th, even though it didn’t
    happen right away or on the same day. i don’t think i will
    be giving him trifexis anymore. i will try revolution next

  273. Karen says:

    Our two dogs, a 50 pound 3-year-old lab mix and a 65 pound 6-year-old chow mix, are both on Trifexis and have been for over a year. Both are fine and have never shown any adverse symptoms from the drug.

  274. Jodi J says:

    Our 45 lb 10 year old standard poodle had his first seizure (ever) within a few weeks of beginning Trifexis. We didn’t “link” the seizure with the meds and kept giving it to him monthly for 7 months, during which time he had 4 seizures, almost exactly every 60 days. We stopped the Trifexis 3 months ago and he has had no seizures since that time.

  275. Erica Levine says:

    Type of dog and age: Rottweiler, 10 mos.
    Side Effects” Labored breathing, diarrhea, lethargy, bizarre behavior
    Started within a week of giving him the meds, has been occurring since. It’s been 3 weeks now.

  276. Earlene C. says:

    My 18month old Basset Hound had been on Trifexis for one year and without any problems. He was reported to be less active and more sleepy during his boarding and 2 play days at his day care center. His dose of Trifexis prior to death, was given on the 24th of Nov. On the night of 28 Nov he had a heart attack and died. I was napping at the time, and upon awakening found him dead on my kitchen floor. I am devastated and grieving immensely. I am not saying that Trifexis is the cause of his heart attack but reported this to the FDA animal division. Will notify Elanco as well. My dog’s veterinarian could not find a cause of my dog’s death. Two weeks prior to his demise, he had his annual exam and everything was fine. He got his rabies shot and parvovirus prevention at that visit. On the 24th of each month he got his Trifexis tablet. A pathology and autopsy was done. He was found to have had an arrhythmia which led to his sudden fatal heart attack. The cause of his death is unknown. I reported his death to the FDA in case cardiovascular effects are found subsequently as this medication is administered.

  277. Christine says:

    Last week, our incredibly healthy and active one and a half year old German Shepherd cried out and died. Our vet thinks she had an unknown heart condition, but she had just taken her third dose of Trifexis the day before. It may be unrelated, but it’s worth noting.

    1. Christine says:

      I just want to update my previous post. I called Trifexis and they had me speak with one of their vets. Dr. Hunt was incredibly kind and sincere. He showed keep concern over the loss of our dog and asked me many detailed questions. At no point did he try to defend Trifexis, the closest thing he said to that was, “In our case studies, we have not had a dog die.” he seemed genuinely concerned and even called our vet to talk with her about our dog’s death. She reported to me that he had called (this was within the hour I had called him) and they discussed my dog’s death and both of them believe she had a heart attack, which I believe is true as well. I was given a case number because they reported my phone call to the FDA. The Trifexis vet thanked me numerous times for calling and said they want to know about these things, even if they may be unrelated, because they want their product to be as safe as possible. T