Genetic mutations in cats

PULLMAN, WASH – WSU researchers in the College of Veterinary Medicine have made a new test for a rare genetic mutation in cats that could affect how they react to medicine. 

The MDR1 gene, also known as the multidrug sensitivity gene, was originally found in dogs in 2001 but has since been discovered in cats by WSU Regents Professor Katrina Mealey.

“We looked at the same gene and we sequenced that gene and there was an affected litter so some of the cats in the litter developed toxicity at the same dose and other cats didn’t,” Mealey said. 

This MDR1 gene can cause cats and dogs to have adverse reactions such as tremors, blindness, lack of muscle control, or even death to common medicines used in things such as spaying and neutering or chemotherapy. 

After Mealey and her team discovered the MDR1 gene in dogs, the Veterinary Poison Center began to experience cats facing problems after receiving certain medications.

“We discovered the mutation in the cats that developed the toxicity that wasn’t there in the cats that did not develop the neurologic toxicity,” Mealey said.

The gene has only been discovered in about 4% of cats, but it appears to be widespread after one of Mealey’s colleagues in Germany found the mutation in a cat there.

Even though this gene is in about 4% of cats, Mealey hasn’t yet found any specific breeds this impacts. This is unlike in dogs where they were able to identify the gene most frequently in herding breeds.

Because this genetic mutation isn’t specified to a single breed, Mealey recommends all cats get tested. There are two options for testing: bring your pet to the vet for a blood sample or there is a cheek swab test you can do right from your home.

All that’s needed for the test is a bit of DNA. After the DNA is collected through either a blood draw or cheek swab, those results are sent in, tested, and pet owners get emailed their results.

The test through WSU is $60 and Mealey said it’s very important to get your pet tested sooner rather than later because there are so many drugs that could trigger this gene.

“So we say test your dog or cat before it’s an emergency so you know what dose of chemo to give them or you know what drugs not to give them,” Mealey said.