By Steve Dale, CABC
Here’s a trivia question: What’s the number one cause of death for indoor cats from around 2 years of age to 8 or 10 years of age? It is most likely feline hypertrophic cardiomyopathy (HCM). According to Joshua Stern, DVM, PhD, DACVIM (Cardiology), Associate Dean for Research and Graduate Studies at North Carolina State, as many as one in eight cats in that age group have hypertrophic cardiomyopathy (HCM).
I had a piano-playing cat named Ricky. He changed my life, and it turns out we now have a treatment for HCM in his name.
At the time, well before YouTube or TikTok, Ricky was a media star. He not only performed “improvisational jazz,” he could literally jump through hoops and jump over dogs lined up on a down-stay. He sat when asked to, and he would even come when called. He went outdoors on a harness and leash, which was unusual at the time, and not only wasn’t fazed but enjoyed the stimulation of going to a pet store to perform a recital or a TV studio.
At the time, cats just did not do this. He became a novel TV star who showed what cats are capable of, and was featured on all sorts of programs, including some Animal Planet shows, National Geographic Explorer, CNBC, a Canadian TV show called The Pet Project, and many other programs, including nearly every local TV station in Chicago (where I live), as well as appearances on WGN Radio, where I worked (and still do). You can even watch one of those TV appearances, from PBS show called Pet Part of the Family.
Of course, Ricky and I had an extraordinary bond.
During one routine veterinary visit, the veterinarian heard a murmur, and the visit turned out not to be so routine after all. A veterinary cardiologist soon confirmed on an echocardiogram that Ricky had an enlarged, thickened heart muscle, a condition known as HCM.
The good news is that, as far as I knew, Ricky had no idea what the diagnosis was. And at least at this point, he appeared to feel fine.
However, most cats with HCM ultimately develop signs that lead to death. One is an aortic thromboembolism, or “saddle thrombus.” This is a serious condition, as also known as ATE, in which a thrombus (blood clot) affects the blood flow to the hind legs of the cat. It’s painful for the cat but can be treated as an emergency. Cats do regain movement of their legs again. The problem is that ATE will usually recur and worsen each time. Not only does this cause the cat great pain, but repeated emergency visits get costly. After several of these occurrences, the victim is usually euthanized.
Other cats with HCM go into heart failure, a condition that requires significant supportive care and medication. Cats can live with heart failure for a time, but ultimately their quality of life diminishes, and they are also euthanized.
Still, other cats with HCM can suddenly die, which is what happened to Ricky. HCM is, by far, the number one cause of sudden death in cats.
The Ricky Fund has supported 38 studies totaling about $350,000, and a lot has been learned. This paved the way for the best outcomes one could hope for. In March, the FDA Center for Veterinary Medicine provided conditional approval for rapamycin or Felycin-CA1 (sirolimus delayed-release tablets) for the management of ventricular hypertrophy in cats with subclinical hypertrophic cardiomyopathy (HCM). This is the first product approved for use in cats with HCM for any indication.
If HCM is detected before actual heart failure, the odds appear (based on clinical trials) that the increase or thickening of the heart returns to normal. It really is a treatment.
I was told repeatedly to give up – that no treatment for HCM could ever be found. But then we were told the same for FIP (feline infectious peritonitis).
The result is simply that countless cat lives will be saved, if HCM is detected. And that means we need to get cats to the veterinarian. After all, veterinary professionals can’t diagnose cats they don’t see.