Heart Disease and Heart Failure in Cats

Heart Disease and Heart Failure in Cats

Animals Affected



Heart disease in cats is caused most often by a condition known as cardiomyopathy.  In this syndrome, the muscles of the heart become unable to perform normally.  As cardiomyopathy progresses it may lead to heart failure (inability of the heart to circulate blood normally through the body) or other serious consequences.

Most heart disease in cats is hereditary.  Most cases of heart disease in cats are not linked to lifestyle, diet, or home care.  Unfortunately, cardiomyopathy is progressive.  Most cases of feline heart disease do not exhibit a strong response to treatment.   Although some cats with cardiomyopathy never show symptoms or develop heart failure, others die from the condition.


Cats with mild heart disease often do not show any signs of illness.  As the disease progresses, however, symptoms of heart failure may develop rapidly.  Symptoms of heart failure include:

Some cats with heart disease suffer sudden paralysis of one or both hind legs.   For other cats, the first symptom of heart disease is sudden death.

Risk Factors and Prevention

  • Cardiomyopathy and heart disease in cats are believed to be largely hereditary.  Maine Coons, Persians, and Siamese cats are at increased risk.
  • Mature cats are more likely to suffer from advanced heart disease than young cats.
  • Hyperthyroidism can contribute to and exacerbate heart disease in cats.
  • A diet with inadequate amounts of the amino acid taurine has been linked to one type of cardiomyopathy in cats.  High quality commercial diets in developed countries are supplemented with taurine.   Therefore, diet-related cardiomyopathy is very rare in developed countries.


Some cats with mild cardiomyopathy never develop symptoms or suffer consequences from the disease.  Unfortunately, many others ultimately develop heart failure.  Many cats with cardiomyopathy die as a result of the condition.

Cardiomyopathy can cause blood clots to form in the heart and then flow into the rear legs of cats.   This leads to sudden paralysis of one or both hind legs.  This serious complication is extremely painful and difficult to treat.   Many cats are euthanized after suffering this complication.

Cats with heart disease are at increased risk of complications from anesthesia.

Cats with cardiomyopathy have difficulty tolerating stress.  They may succumb to stress from heat, car travel, grooming, or veterinary procedures.

Cats with heart disease sometimes die suddenly from acute massive heart failure.


Cardiomyopathy is diagnosed through a combination of physical examination and diagnostic tests including electrocardiogram (ECG), X-rays, and ultrasound (echocardiogram).  Blood and urine tests usually are run to evaluate for thyroid disease and other concurrent illnesses.

Some cats with heart disease have a heart murmur that can be detected during a physical exam.  Many others, however, exhibit no outward signs of disease.  Because of this, many cases of cardiomyopathy are not diagnosed until the disease is advanced.


Cats with heart disease should not be placed in stressful situations.  They should not be exposed to extreme heat.

Medications are often prescribed to improve the function of the heart.   Medications used for this purpose include diltiazem, atenolol, propanolol, enalapril, and benazepril.

Cats in heart failure may receive medications such as furosemide (Lasix®) to remove fluid from the lungs.  Fluid-filled areas of the chest or abdomen may be drained manually by veterinarians.

Small quantities of aspirin may be prescribed to reduce the likelihood of blood clot formation and paralysis of the hind legs.

If present, thyroid disease is treated to reduce its effects on the heart.

Although some cats show clinical improvement when treatment is implemented, many others do not show a marked response to the treatments listed above.  Because of this, treatment of heart disease in cats is often frustrating and unrewarding.


For cats with symptoms of heart failure, success of therapy is based primarily upon its effect on the symptoms.

Cats with heart disease require follow-up X-rays and echocardiograms at periodic intervals.  Regular blood tests are recommended to assess the function of other organs in the body.


Cats with cardiomyopathy do not tolerate stress well.  They sometimes suffer complications during veterinary procedures.  Because of this, veterinarians are not able to perform full diagnostic evaluations on all cats with heart disease.


Copyright © Eric Barchas, DVM All rights reserved.
The contents of this page are provided for general informational purposes only. Under no circumstances should this page be substituted for professional consultation with a veterinarian.