The effectiveness of a commonly prescribed treatment for hypertrophic cardiomyopathy (HCM) in cats may vary depending on the animal’s genes. Veterinarians at the University of California, Davis (UC Davis), have found a cat’s DNA alters how it responds to clopidogrel, a medication used to treat HCM, a heart disease that affects one in seven cats. HCM causes a cat’s heart muscle to thicken, and, as the condition worsens, blood clots can form in the heart. Dislodged clots can lead to pain, distress, and even sudden death, UC Davis says. Clopidogrel is among the most commonly prescribed medications to prevent blood clots in cats with HCM; however, data examined by the study’s researchers revealed nearly 20 percent of cats receiving clopidogrel therapy showed resistance. “We were consistently seeing cats that, despite being on clopidogrel, were still forming blood clots,” says the study’s corresponding author, Joshua Stern, DVM, PhD, professor of veterinary cardiology and geneticist at UC Davis School of Veterinary Medicine. “This study was about figuring out why some cats weren’t responding as expected to clopidogrel therapy and leading us towards a more effective prescription.” In a clinical trial of 49 cats, researchers first tested the animals’ ability to form clots, then had the cats’ owners administer clopidogrel for a period of 14 days. They then tested whether mutations in the cat genome impacted the effectiveness of the medication. “The end result is the ability to use a simple genetic test to make an educated decision about which drug therapy may be best for preventing blood clots in cats with HCM,” Dr. Stern says. While testing like this is not yet commercially available, UC Davis researchers hope veterinarians will ultimately be able to rapidly test cats with HCM for these mutations. Ultimately, this could help in developing more personalized medicine for cats, allowing veterinarians to test kittens for a host of genetic variants to help inform medical decisions and treatments throughout the animal’s life. “We are very excited to be approaching this era where personalized or precision medicine in animals can catch up to precision medicine in humans,” says co-author Ronald Li, DVM, MVetMed, PhD, an assistant professor of veterinary emergency and critical care and coagulation researcher, whose lab conducted much of the functional testing of the anticoagulant therapies. “Just as we can’t expect every human to respond to medication in the same way, we can’t expect all cats to respond the same way either.” The findings have been published in Scientific Reports. Written with files from UC Davis.
