HCM in Ragdoll Cats
By Dr. Kevin Toman, DVM · Medically reviewed November 1, 2026 · 40+ years in clinical practice · 300+ cats with HCM treated
Short answer: Ragdolls have a known gene change (called MYBPC3-R820W) linked to HCM, a disease that thickens the heart wall. Cats with two copies have the highest risk. A DNA test shows risk, but only a heart ultrasound shows whether HCM is actually there. A negative gene test does not rule HCM out.
Why Ragdolls are at higher risk
HCM (hypertrophic cardiomyopathy) makes the heart's main pumping wall too thick and stiff. Any cat can get it. Ragdolls have their own breed-specific gene change that raises the risk.
It's in the same gene as the Maine Coon mutation (MYBPC3), but it's a different change. A Maine Coon test does not work for Ragdolls, and the reverse is also true.
How the Ragdoll gene works
| Gene result | What it means | Risk |
|---|---|---|
| Negative (N/N) | No copies | Lower risk, but HCM is still possible |
| One copy (N/HCM) | Carrier | Higher risk. Disease may be mild or never appear. |
| Two copies (HCM/HCM) | Got it from both parents | Highest risk. Often earlier and more severe disease. |
Scientists call this "dominant with incomplete penetrance." In plain words: one copy can be enough to raise the risk, but not every cat with the gene gets sick. Proven
From Dr. Kevin's 400+ Cats with HCM
Because the presence of the ragdoll gene variant does not guarantee HCM one way or another, I always recommend using a simple blood test known as the pro-BNP test for screening. It measures heart muscle stress, is cheap, and takes only a couple drops of blood.
Do this once a year. It may give us the early warning your cat needs for best treatment.
Symptoms to watch for
Early HCM often has no signs. When signs appear, they may include:
- A heart murmur or gallop sound
- Less play or energy
- Faster breathing while asleep
- Breathing that looks like hard work
- Poor appetite
- Collapse
Some Ragdolls with HCM have no murmur at all. A healthy-looking Ragdoll can still have heart disease.
Go to an emergency vet now for open-mouth breathing, struggling to breathe, collapse, or sudden back-leg weakness or pain.
How HCM is diagnosed in Ragdolls
- Echocardiogram (heart ultrasound): the main test. It shows heart wall thickness and left atrium size.
- Gene test: shows inherited risk. It is not a diagnosis.
- Blood pressure and thyroid tests: rule out other causes.
- ECG or NT-proBNP blood test: helpful in some cats.
When should a Ragdoll be screened?
- Breeding cats: gene test, plus heart ultrasounds before breeding and regularly after.
- Cats with two copies: start screening early. Ask a cardiologist about timing.
- Cats with one copy or a family history: regular ultrasounds, often every 1 to 2 years.
- Any Ragdoll with a murmur, gallop or breathing change: get an ultrasound now.
One normal scan does not mean lifelong protection.
Buying a Ragdoll kitten? Ask the breeder
- Were both parents tested for MYBPC3-R820W? Can I see the results?
- Did both parents have heart ultrasounds? When, and by whom?
- Has any related cat had HCM, heart failure or sudden death?
- What is my kitten's gene test result?
A gene test is one part of responsible breeding. It does not replace heart screening.
If your Ragdoll has HCM
First, find the stage (A, B1, B2, C or D). Many Ragdolls stay stable for years. The left atrium's size and function matter most for the outlook. Learn about Stage B2 →
Treatment options may include:
- Clopidogrel to lower clot risk in higher-risk cats
- Felycin-CA1, a weekly sirolimus tablet. FDA conditionally approved in 2025 for cats with HCM and no symptoms. It targets the thickening itself. Promising Read the Felycin guide →
- Heart failure drugs if fluid builds up
Is your Ragdoll a Felycin candidate? Take the 3-minute check → [DR. KEVIN: add link]
Outside the US?
We ship Felycin routinely to the US, UK, and Canada. You start by sending your vet's prescription, or by enrolling your cat in our Cat Longevity Protocol. You can purchase Felycin from us and get guaranteed delivery, although it sometimes takes a few days.
If you live in the EU, Taiwan, Hong Kong, or China you can purchase Felycin from us. You start by enrolling your cat in our Cat Longevity Protocol. You provide the shipping, and we cannot guarantee delivery but we can absolutely send it your way.
Frequently asked questions
Are Ragdolls more likely to get HCM?
Yes. They have a known breed-linked gene that raises the risk.
Can a Ragdoll with a negative gene test get HCM?
Yes. The test checks only one mutation. Other causes exist.
Does the Maine Coon gene test work for Ragdolls?
No. The two breeds have different mutations, so each needs its own test.
Can Ragdoll HCM be cured?
Not yet. New treatments like Felycin target the thickening, but there is no cure.
Can Ragdolls with HCM live normal lives?
Yes. Many stay stable for years and some have a normal lifespan.
Your next step.
Have your Ragdoll's gene test or echo report and not sure where to go? Enroll in our Cat Longevity Protocol and get a FREE Consult with Dr. Kevin
Free guide: HCM University · Related: HCM in Maine Coon Cats
References
- Luis Fuentes V, et al. ACVIM consensus statement on cardiomyopathies in cats. J Vet Intern Med. 2020;34(3):1062–1077.
- Meurs KM, et al. A substitution mutation in the myosin binding protein C gene in Ragdoll hypertrophic cardiomyopathy. Genomics. 2007;90(2):261–264.
- Borgeat K, et al. Association of the myosin binding protein C3 mutation (MYBPC3 R820W) with cardiac death in a survey of 236 Ragdoll cats. J Vet Cardiol. 2014;16(2):73–80.
- UC Davis Veterinary Genetics Laboratory. Hypertrophic cardiomyopathy (Ragdoll).
- US FDA. Conditional approval of Felycin-CA1. March 2025.
This article is for education only. It does not replace an exam, diagnosis or treatment plan from your own veterinarian. Prices and regulations change; confirm locally.