Your cat’s veterinarian hears a murmur. What does that mean? Maybe nothing — maybe something. A cat heart murmur or a gallop (a kind of irregular heartbeat) might mean feline hypertrophic cardiomyopathy (HCM), or abnormal thickening of the heart.
Although some cats have HCM for a lifetime, and never suffer from an outward symptom, HCM is the most common cause of sudden death in cats. Often, cats otherwise appear healthy — the way pro athletes who suddenly drop on the court or field do.
Advances in Feline HCM Research
Dr. John Rush, veterinary cardiologist at Cummings School of Veterinary Medicine, Tufts University, spoke to 130 veterinary professional and cat breeders at the 34th Winn Feline Foundation Annual Symposium in Quincy, Mass., last month. Rush explained that there is good news.
Due directly to Winn Feline Foundation’s funding, geneticist Dr. Kate Meurs has identified gene defects in two cat breeds, the Ragdoll and the Maine Coon. With a simple cheek swab, an inexpensive genetic test can determine if the defect for HCM exists in individuals. Rush noted that the test is imperfect, but is still a tool to guide breeding programs that has saved lives.
Rush also discussed a new, inexpensive blood test called proBNP, or Cardiopet, developed for cats by IDEXX Laboratories.
What Happens to Cats with HCM?
A murmur (distorted heartbeat), gallop (a third audible heart sound) or rapid heartbeat all signal potential HCM. Then again, many cats with a murmur or gallop or speedy heartbeat have no heart disease.
Prior to Cardiopet’s availability, the next step for cats with murmurs, gallops or rapid heartbeats might have been an expensive echocardiogram. Some people refuse because they weigh the odds that their cats really have HCM against the high cost of the test.
The huge advantage of Cardiopet is that the result from this inexpensive blood test may instantly put the cat owner at ease, so no further testing is required. It may very well turn out that the murmur or gallop is benign, or the rapid heart rate is explained because the kitty is nervous at the vet’s office.
That’s one possibility; another possibility is that the test result might suggest cat heart disease is possible. If that’s the case, then an echocardiogram is suggested.
Another use of Cardiopet is to distinguish between respiratory disease and heart disease. In cats, the symptoms are nearly identical. If it turns out that a cat has respiratory disease (likely due to cat heartworm) that expensive echocardiogram isn’t necessary.
Rush explained that the drugs used for HCM, used for several years, at best may slow the progression of HCM. They offer no definitive extension of life. The Winn Feline Foundation has supported funding for studying the effectiveness of other drugs, but, so far, no pill has panned out as a magic bullet.
Further Research for Feline HCM
As common as HCM is, these advances are as far as treatment and detection have gone. The Winn Feline Foundation Ricky Fund, named for my cat, continues to raise money to fund veterinary studies; the idea is indeed to spend the money on studies, but the result is that the Ricky Fund hasn’t been replenished as fast as money has been spent.
Learn more about HCM and the Ricky Fund here.