Feline hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats, and also the most common cause of sudden death in cats. Yet, veterinary medicine knows little about this often debilitating disease.
Information on HCM is limited. The Winn Feline Foundation’s Ricky Fund supported an ongoing 10-year retrospective study, and the results were recently published in the Journal Veterinary Internal Medicine. One surprising finding: Fewer than 25% of all HCM cats in the study ever showed any discernible symptoms. One outcome of this study confirms that if your cat ever gets HCM, it’s not necessarily a death sentence.
Still many cats die as a result of HCM. In fact, HCM might even cause the most deaths in adult cats. HCM is inherited in some cat breeds, and also occurs within some families of domestic shorthair cats, as well as various purebred cats.
We have much more to learn about HCM. Few studies have truly focused on phenotype (what a cat looks like) and the relationship to HCM. Results from a retrospective study of 344 cats representing four breeds, as well as domestic shorthair cats, are revealing.
The JVIM published results represents four breeds, all among breeds shown to carry HCM): Persian, Sphynx, Maine Coon and Chartreaux, as well as domestic shorthair cats. Each cat had HCM.
Among cats with HCM, 266 individuals were actually asymptomatic, while only 78 had signs of disease –from generalized weakness to thromboembolism (suffering at least one stroke-like attack), syncope (fainting spells) to actual heart failure.
Age of first heart attack in Maine Coons (2.5 years) versus other breeds (7 years) was much younger. In Sphynx, the age at the time of diagnosis was 3.5 years. With sudden death, Maine Coon cats died younger in this manner compared to other breeds. No sudden deaths were reported in Chartreux and Persian cats in this study. Sudden death occurred in only two of the breeds — Maine Coon and Sphynx — as well as in domestic shorthairs. All cats surviving longer than 15 years of age were domestic shorthairs, Persians or Chartreux.
After my own cat, a Devon Rex named Ricky, died of HCM in 2001, I realized by how little was known about this common disease, and I was moved to initiate the Ricky Fund at the Winn Feline Foundation to support studies to better understand HCM. We’ve raised over $100,000 and have made a difference – at least among Maine Coon and Ragdoll cats, where a gene defect has been identified. With a simple cheek swab, breeders can determine if a cat is carrying the responsible gene. Though the test is imperfect and doesn’t account for all cats, it’s a start. You can learn more about the Ricky Fund, and consider a contribution, here.