Cat Hypertrophic Cardiomyopathy: Detection and Management

Hypertrophic cardiomyopathy is the most common heart disease in cats, often causing sudden death or severe respiratory distress. Early detection allows management that extends comfortable life.

Key Facts

HCM affects approximately 15% of the general cat population and up to 26% in Maine Coons
The condition causes thickening of the heart muscle, reducing its ability to fill and pump effectively
Many cats with HCM have no symptoms until sudden decompensation, respiratory distress, or aortic thromboembolism
Aortic thromboembolism — a blood clot blocking the hind limb arteries — causes sudden acute paralysis and extreme pain
Genetic testing is available for Maine Coon and Ragdoll HCM mutations but does not detect all forms
Regular cardiac ultrasound screening every 1-2 years is recommended for predisposed breeds

Welfare Considerations

HCM kills cats silently, without warning signs, or causes acute crises such as aortic thromboembolism that are among the most painful events a cat can experience. The sudden paralysis and pain of a thromboembolism are distressing for both cat and owner. Early detection through screening allows initiation of treatment before crisis, and in some cases significantly delays disease progression.

What You Can Do

Ask your vet about cardiac screening for Maine Coons, Ragdolls, and British Shorthairs
Have your cat's heart listened to by a vet annually as part of a routine health check
Learn to recognise signs of respiratory distress — rapid breathing, open-mouth breathing, blue gums are emergencies
Ensure your cat insurance covers cardiac conditions including HCM
Support genetic testing programmes to identify HCM mutations in breeding cats
Discuss medication options with your vet if HCM is diagnosed — some drugs slow progression