Hypertrophic cardiomyopathy (HCM) in cats
HCM is a thickening of the heart muscle. It's the most common heart disease in cats, and Maine Coons and Ragdolls can inherit it.
Last updated: October 2026 · 2 sources · see sources
Signs to watch for
- Often none
- Fast or labored breathing
- Hiding
- Sudden hind-leg paralysis from a blood clot
Trouble breathing, collapse, repeated vomiting, not peeing, or a seizure that lasts more than a few minutes needs a vet right away. See when to see a vet.
How vets diagnose it
An echocardiogram is the main test. Chest X-rays, NT-proBNP and blood pressure help too. [2]
How it's treated
Treatment can include clopidogrel to reduce clot risk, diuretics for heart failure and other heart medicines. [2]
Medicines your vet may mention: Clopidogrel (Plavix), Furosemide (Lasix), Atenolol. We don't list doses; your vet will decide what fits your pet.
What it costs to diagnose and manage
| Item | Typical US price | Src |
|---|---|---|
| Diagnosis (exam and tests) | $400–$1,000 | [1] |
| Ongoing treatment, per month | $30–$200 | [1] |
| Ongoing treatment over a year (monthly range × 12) | $360–$2,400 | [1] |
These are typical US ranges from the sources listed. Your pet's costs depend on how severe things are, the tests your vet recommends, your pet's size and where you live. Ask your vet for a written estimate.
Outlook
Some cats live normally for years; others develop heart failure or clots. Counting resting breaths at home helps. [2]
Common questions
What is hypertrophic cardiomyopathy (HCM) in cats?
HCM is a thickening of the heart muscle. It's the most common heart disease in cats, and Maine Coons and Ragdolls can inherit it.
What are the signs of hypertrophic cardiomyopathy (HCM)?
Common signs include: often none, fast or labored breathing, hiding, sudden hind-leg paralysis from a blood clot.
How do vets diagnose hypertrophic cardiomyopathy (HCM)?
An echocardiogram is the main test. Chest X-rays, NT-proBNP and blood pressure help too.
How is hypertrophic cardiomyopathy (HCM) treated?
Treatment can include clopidogrel to reduce clot risk, diuretics for heart failure and other heart medicines.
How much does hypertrophic cardiomyopathy (HCM) cost to treat?
Diagnosis (exam and tests): $400–$1,000; Ongoing treatment, per month: $30–$200; Ongoing treatment over a year (monthly range × 12): $360–$2,400. Costs vary with severity, tests, your pet's size and where you live.
Related
This page is general information for pet owners, not veterinary advice. Talk to your vet about your own pet.