As a pet coach who’s worked with Sphynx cats for many years, I know firsthand how devastating it can be when a heart condition like HCM (Hypertrophic Cardiomyopathy) sneaks up on you. HCM is often called a silent killer because it can remain completely undetected until it’s far advanced, which is why I’m so passionate about early screening and awareness.
So today we’re talking about the symptoms to look out for.
What Are the Signs of HCM in Cats?
Some of these symptoms may be subtle, and others may come on suddenly and require emergency attention.
Common signs include:
Lethargy or sudden drop in activity level
Labored breathing, rapid breathing, or open-mouth panting (especially after exercise)
Loss of appetite
Detection of a heart murmur or arrhythmia at the vet
Coughing, wheezing, or fluid in the lungs
Thromboembolic events (blood clots that may cause sudden pain, paralysis, or collapse—most often in the hind legs)
Fainting, weakness, or collapse
Weight loss, cold or pale gums, weak pulse
Abdominal swelling from fluid retention
Now here’s the catch…
HCM Is Often Symptomless Until It’s Too Late
Many Sphynx cats won’t show any of these signs until they are in late-stage heart failure or experiencing a blood clot emergency. That’s why you cannot wait for symptoms to start routine care.
What You Should Do Instead
Schedule a heart scan (echocardiogram) with a licensed veterinary cardiologist at least every two years.
In between scans, ask your vet to perform a ProBNP blood test - this can detect early signs of heart inflammation or damage.
Be proactive and consistent with wellness checks, especially if your cat’s breed is high-risk for HCM like the Sphynx.
So please, don’t rely on your eyes alone. HCM is often invisible, until it isn’t. Put a regular heart checkup on your calendar and talk to your vet about ongoing screenings.
