Treatment Options for Heart Murmur in Cats

Detecting a heart murmur in your cat is the first step to determining if any underlying heart diseases or other problems are putting your cat at risk for something more serious.

Defining a Heart murmur

Heart murmurs are not an illness. Nor are they a disease. Murmurs are simply an abnormality in the sound of the heart. Many cats live their entire lives with murmurs that cause no problems, and in fact a murmur may only be detected through routine vet checkups. Murmurs can be congenital, meaning the cat is born with it, or a cat can develop one over time. Some more serious heart murmurs can indicate underlying problems, most commonly heart disease. How a heart murmur is treated, or if it is treatable, depends on the disease or problem behind it.


One of the two most common causes of heart murmurs is hyperthyroidism. Hyperthyroidism is a result of an enlarged thyroid gland producing too many hormones. This enlargement is caused by a non-cancerous tumor. It can be treated in a number of ways, including surgery to remove the gland, although this is usually a last resort. There are a number of medications that can be tried first, as well as radioactive iodine.

Prognosis for hyperthyroidism greatly varies on a case-by-case basis. Condition of the kidneys and heart must be taken into consideration.


Cardiomyopathy is the most common heart disease among cats and the second most common cause of heart murmurs. Hypertrophic cardiomyopathy, or HCM, is when parts of the heart harden or stiffen, and results in improper blood flow to the body. Restrictive cardiomyopathy, or RCM, is a chamber of the heart unable to properly expand due to fibrosis.

A variety of treatments are available, such as using low doses of aspirin to inhibit platelet function, or amlodipine to reduce blood pressure so the heart is not working so hard. Using an angiotensin converting enzyme (ACE) inhibitor can also reduce the heart's work load. Calcium channel blockers allow the heart to relax so more blood can fill the chambers.

Internal or External Parasites

Anemia can be another cause of heart murmurs. Anemia can be brought about by parasites - both internal (such as hookworms) or external (such as fleas). Parasites drain nutrients and blood from the cat's body, in turn causing a series of other problems that are not only limited to heart murmurs.

Treatment for parasites is usually as simple as obtaining the appropriate medication. In the case of fleas or ticks, owners can administer proper care and treatment to get rid of them and prevent future infestations.

At Home Treatment

Cats with heart murmurs as a result of heart disease need to be kept relaxed and calm, as exercise, excitement and stress can worsen the problem. Preferably, the household should be quiet and warm, without other pets or small children who might disturb the sick cat. If children or other pets are present in the house, you might need to take extra steps to ensure your cat is getting the rest he needs, and is not being stressed out. This may mean giving him his own food, water and litter box in a quieter room in the house where he can go to be alone.