Dog ate chocolate?

ask a vet

Heartworm and MDR1

Species: Dog
Breed: 1. Aussie, 2. Lassie
Age: 2-5 years
I rrecently had both dogs genotyped for MDR1 mutation and both are positive. Bella is mutant/mutant, Khodi Normal /mutant. Isabella especially get very sick on heartguard and both are mildly on advantix. Ivermectin, Milbemycin, Selamectin and Moxidectin are all on the list of drug sensitivities for MDR1 positive dogs. What can I use for heart worm prevention?


Online vet, Dr. Marie

Dr. Marie replied:

Ultimately this is a question that needs to be answered by your vet as they are aware of which heartworm medications are the most effective in your area.

However, all of the products that you have mentioned are considered safe for dogs with an MRD1 mutation. Even though they contain a tiny amount of ivermectin or a derivative of ivermectin it has been shown to be extremely safe at the dosages contained in these drugs.

I wrote an article that discusses her these dosages and what is safe for these dogs by with an MDR1 mutation.

What kind of reaction do the dogs have? If dogs are reacting to ivermectin the reaction is usually a neurological one. You can see tremors and twitching and things like that. If that is not what you were seeing then there may be something other than ivermectin sensitivity going on.

Unfortunately, I am not aware of an alternative for you.

Dr. Marie


Do you have a pet website? Interested in learning more about SEO for Wix?


Check out our dog age calculator and cat age calculator.

Want to receive pet coupons, vet advice and info on new pet products in your inbox?

* indicates required

We'll only send you great stuff, never spam. Unsubscribe any time.

Disclaimer: Although Dr. Marie is a qualified veterinarian, the information found on this site is not meant to replace the advice of your own veterinarian. AskAVetQuestion.com and Dr. Marie do not accept any responsibility for any loss, damage, injury, death, or disease which may arise from reliance on information contained on this site. Do not use information found on this site for diagnosing or treating your pet. Anything you read here is for information only.

Search for similar questions:

ask a vet

Popular questions...

Itchy dog. Desirae was gave to us,she was dirty and i belive she was kept outside,when we got... (6225 views)

Dog afraid of dogs and people. hello i have a 7 month old puppy and every time she comes into cintact with another... (8966 views)

Dog is limping after back surgery. Chloe is 9yrs of age. She has been lame in her left hind leg for the past 3 yrs but... (9324 views)

Aspirin and Lasix? Hello. My regular vet is out of town and my dog is in a lot of pain. He's thirteen... (10170 views)

Dry nose in a dog. is it normal that my 10 year old dog haves a very dry nose everytime?... (8407 views)

Cat pooping on floor. We have a male, neutered cat who is about 4 years old. He has been pooping on the... (11361 views)

Cause of high ALP? mickey a male is 6 and 1/2 years old. he was prescribed on 8/12/11 rimadyl (1/2 75mg... (12996 views)

Vacuolar hepatopathy. Hi Dr. Marie I am following up with you regarding Oreo's elevated bile acid... (20409 views)

Should liver biopsy be done? Dear Dr Haines, I have a 10 year old Bichon-Poodle-Maltese mix male dog (Max). ... (6999 views)

Large mammary glands. Our dog is a black + tan kelpie and has just had her first litter of puppies, six in... (10891 views)

See all questions...

Dr. MarieDr. Marie is a veterinarian who practices in a busy animal hospital in Ottawa, Ontario. She created Ask A Vet Question as a resource for good, accurate veterinary advice online. Dr. Marie treats dogs, cats, hamsters, guinea pigs, and rats. She has been a vet since 1999.

Is an online vet visit just as good as a trip to your veterinarian? No! But, many times, asking an online veterinarian a question can help save you money. While Dr. Marie can't officially diagnose your pet or prescribe medications, she can often advise you on whether a vet visit is necessary. You can also ask Dr. Marie for a second opinion on your pet's condition.