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


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...

Homemade chicken jerky treats for dogs. Hi Dr. Marie, If you do choose to answer my questions, I thank you so much in... (5062 views)

Older cat problems. My cat is eating constantly. Every hour or two she cries at me to eat. And she's... (9817 views)

Can a dog get lice? Can my dog get lice... (5495 views)

Sick puppy. Our Westie puppy, Minnie, is 12 weeks old today. We got her 23 days ago. From Day... (10222 views)

Tumor behind eye. hi dr marie,enjoy your website and read all the dog related problems! my girl... (10053 views)

Limping after cat fight. Hello, My cat recently had a fight with another cat. Now he is limping on his left... (10311 views)

Chihuahua ate tennis ball. My small, 5lb baby girl chihauha (sp?) was outside playing with our two other dogs. ... (19799 views)

Puppy has red weepy eyes. my puppies eyelids on the inside are very red and his eyes have been weeping a lot,... (10490 views)

Renal failure. Dear Dr. Marie, My 10 year old Yorkie Bobo has been diagnosed with chronic kidney... (14162 views)

Losing weight but lab tests normal. My cat is losing weight, vomiting, more vocal than normal, lethargic and hungry all... (10458 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.