Most cats with heart disease show no symptoms until heart failure or blood clot strikes suddenly. Daily observation of small changes is the earliest warning system available to you.
Count your sleeping cat's breaths per minute. Consistently above 30 per minute is an early sign of heart failure.
Cats almost never breathe through their mouths when calm. This is an emergency sign — pulmonary edema or pleural effusion.
No longer jumping to favorite spots, less interest in play. Heart muscle weakness causes easy fatigue.
Aortic thromboembolism (ATE) — a blood clot blocking the rear leg arteries. Accompanied by intense pain. This is a critical emergency.
Arrhythmia or low blood pressure causing a brief loss of consciousness. Even if recovery is rapid, always see a vet.
Advanced heart failure reduces appetite. Usually accompanied by progressive weight loss.
HCM is the most common heart disease in cats. The walls of the heart — particularly the left ventricle — thicken abnormally, reducing the heart's ability to fill with and pump blood. Breeds with known genetic predisposition include Maine Coons, Ragdolls, and British Shorthairs, but mixed-breed cats are also affected.
The insidious nature of HCM is that early and middle stages are often completely symptom-free. Cats are stoic and naturally hide weakness. Many cases are discovered incidentally during routine physical examinations — through a new heart murmur or abnormal cardiac exam.
By the time symptoms appear, heart failure has usually already developed — either pulmonary edema (fluid in the lungs causing breathing difficulty) or ATE (blood clot causing sudden limb paralysis). Annual vet checkups including cardiac auscultation and, for at-risk breeds, echocardiography are the best form of early detection.
CatsMe makes it easy to log your cat's resting respiratory rate and activity level every day. Building a consistent baseline means any change is immediately visible — and you'll have data to share with your vet that goes beyond 'I think something's off.'
Get Started FreeHCM cannot be reversed, but medications (ACE inhibitors, beta-blockers, anticoagulants) can slow progression, prevent clots, and delay the onset of heart failure. Cats caught in the preclinical stage can often live comfortably for years with proper management.
Cardiac ultrasound (echocardiogram) costs approximately $200–$600 depending on your location and whether a cardiologist performs it. A proBNP blood test ($50–$150) is a useful preliminary screening tool. Annual checkups are recommended.
While your cat is asleep and relaxed, count the number of times the chest rises in 15 seconds, then multiply by 4. A normal resting rate is 15–30 breaths per minute. If you consistently see 30+ over several days, contact your vet.