How to Treat Cats with Hypertrophic Cardiomyopathy

Doctor veterinarian at clinic.

While everything may appear to be fine on the surface, your cat may be suffering from an inside problem. Cats are unfortunately particularly susceptible to hypertrophic cardiomyopathy, which is a silent condition. Although some cat breeds are more susceptible to the disease than others, it is something that all cat owners should be aware of. Knowing what indications to look for might help you catch this condition early.

What Is It?

Hypertrophic cardiomyopathy (HCM) is a cardiac disorder in which the walls of the heart, particularly the left ventricle, thicken. This makes it more difficult for the heart to function correctly. The heart is a muscular organ with chambers that pump blood. If the heart's walls become too thick, it will be unable to adequately pump blood. Although the left ventricle is one of four heart chambers, it is responsible for pumping blood throughout the body. If it fails to fulfill its function, blood flow to the rest of the body is disrupted.

If the heart isn't operating correctly, blood can back up and clots can develop. In HCM, the heart tries to compensate for the lack of normal blood supply by beating faster. It does so by depleting the body's oxygen supply, which causes cardiac cells to die. When cells die, the heart's function deteriorates even more, resulting in irregular heartbeats. Congestive cardiac failure is also prevalent in cats with HCM, partly as a result of the blood backlog.


Because HCM happens internally, it often comes as a surprise to cat owners. Heart issues may not be obvious until a cat is having problems, so it is important to know what to watch for.

Auscultation, or listening to your cat's heart with a stethoscope, is part of a thorough medical checkup. Your veterinarian will listen for a regular heartbeat, a murmur, or an arrhythmia. If you hear an arrhythmia or a murmur, it might be a sign of cardiac illness such hypertrophic cardiomyopathy. To check your cat's heart further, an X-ray and an ultrasound of the heart, known as an echocardiography, may be needed. These tests will not cure a cardiac disease, but they will provide your veterinarian with a diagnosis and, as a result, a treatment plan.

Observing your cat take fast breaths can frequently reveal labored breathing. Audible wheezes, the tummy rising and falling instead of the chest, an open mouth or heavy panting, and pale or blue gums are all signs of a cat straining to breathe. Your cat will have trouble breathing and may get weak or collapse if it can't carry oxygen through its lungs.

HCM may sometimes cause sudden hind limb paralysis, which is a frightening sign. Your cat will look paralyzed if a clot travels from the heart and limits blood supply to the hind limbs. This can happen abruptly, and the limb will feel chilly to the touch owing to the lack of blood flow. Clots can sometimes cause sudden death, but this is uncommon.


  • Open-mouth breathing
  • Pale or blue gums
  • Collapse
  • Weakness
  • Irregular heartbeat
  • Hind limb paralysis
  • Sudden death


Hypertrophic cardiomyopathy is more common in certain cat breeds than in others. Maine Coonhounds, Ragdolls, Persians, Sphynx, Chartreux, and British Shorthair breeds have all been found to have a genetic susceptibility to HCM and are hence more likely to acquire it. It's unclear why some breeds are more susceptible than others to develop HCM. However, if you have one of these cats, it's very vital to keep a careful eye on their heart condition to diagnose HCM early.

Other cat breeds can potentially get hypertrophic cardiomyopathy, however the cause is unknown. Although some dietary components and obesity may have a role in cardiac disease in cats, there is no conclusive evidence linking hypertrophic cardiomyopathy to a single cause.


Because hypertrophic cardiomyopathy cannot be cured, the purpose of treatment is to keep your cat's heart rate regular, avoid blood clots, and make breathing easier for him. While this is more of a management strategy than a treatment strategy, it is the best choice until a cure or further research is available.

  • Nutrition: Taurine and L-carnitine are amino acids that are often recommended as supplements for cats with heart disease. These are often added to pet food and are also produced naturally within a cat's body. Research has shown that they may be beneficial in supporting a healthy heart but they are not treatments of hypertrophic cardiomyopathy specifically, just overall heart health. Omega-3 fatty acids and special diets formulated for cats with heart disease may also be beneficial in supporting cats with hypertrophic cardiomyopathy.
  • Medications: There are several drugs that might be prescribed to help manage the symptoms of HCM. Some medications may be injected, applied topically, or administered in pill form. Different drugs will help make breathing easier, assist the heart's function, stabilize blood pressure, and address other potential symptoms of HCM.
  • Activity level: Your veterinarian may recommend keeping your cat's activity level low in order to decrease the amount of work its heart has to do.


There is no way to determine if you are avoiding hypertrophic cardiomyopathy because there is no recognized conclusive cause. Providing regular cardiac nourishment and ensuring your cat has an annual veterinary inspection will help keep your cat healthy and reduce the risk of disorders such as hypertrophic cardiomyopathy.


If hypertrophic cardiomyopathy is suspected, blood tests, X-rays, blood pressure testing, and an echocardiography will most likely be conducted to properly analyze your cat's condition. Your veterinarian will propose a treatment plan based on the results of those tests to help alleviate symptoms and slow disease development.

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.