Problem medications for cats

Since the feline MDR1 mutation was more recently discovered than the canine MDR1 mutation there has been less research on the topic. The WSU PrIMe research team is working to determine if other drugs commonly used for treating cats are substrates for feline P-glycoprotein (i.e., have the potential to cause toxicity in cats with the […]

Close up image of grey tabby cat with white on it's chin, neck and front paws.

Problem medications for dogs

Learn what medications may be dangerous for your dog with the MDRI genetic mutation. Dogs with the MDR1 genetic mutation can become very ill or die if given certain medications. WSU is the leader in identifying drugs that may be dangerous for dogs with the MDR1 mutation and can identify alternative medications and doses. Once WSU has determined your dog’s […]

Australian Sheppard running through water.

Is your pet at risk of an adverse reaction to common drugs?

What is multidrug sensitivity? Some dogs and cats have a mutation in the MDR1 (multidrug resistance 1) gene also known as the ABCB1 gene, which plays an important role in limiting drug distribution to the brain and in enhancing the excretion of many drugs. Animals with the mutation may have severe adverse reactions – including […]

Are heartworm prevention products safe if my dog has the MDR1 mutation?

All heartworm products labeled for dogs in the United States have been tested in dogs with the MDR1 mutation as required by the FDA and have been found to be safe. Drugs such as ivermectin, selamectin, milbemycin, and moxidectin, are commonly used to treat and prevent parasites like heartworms. At low doses, such as those […]

Dog breeds commonly affected by MDR1 mutation

Dogs with a mutation in the MDR1 (multidrug resistance 1) gene may have severe and life-threatening reactions to some common drugs. Research has shown the mutation occurs more frequently in certain breeds. Approximately three of every four collies in the United States have the mutant MDR1 gene. The frequency is about the same in France […]

Rough Collie