What Does a Heart Murmur Mean for Your Cat?

Vet Exam
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As a cat owner, it can be upsetting to find out that your cat has a murmur. Feline heart murmurs are generally detected during a physical examination when the veterinarian listens to your cat's chest with a stethoscope. This might catch you by surprise if you simply went in for her annual checkup, so it's a good idea to understand what causes a murmur and what your next step might be.

What Is a Heart Murmur?

A heart murmur occurs when there is turbulence in the blood as it flows through the heart. The murmur is audible as a whooshing or swishing sound that occurs during the normal cycle of the heartbeat.

Potential Causes of Heart Murmurs in Cats

There are many different conditions that can cause a heart murmur in a cat. Some of these conditions are serious and can be life-threatening. Others are benign, not related to a disease, and may not affect your cat's health.

  • Heart murmurs in cats can be related to congenital heart diseases, such as pulmonic stenosis or patent ductus arteriosus (PDA).
  • Feline heart murmurs can also be associated with cardiomyopathies (diseases of the heart muscle).
  • The heart murmur may be constant, which means it is always audible at the same level of intensity. In other words, it always sounds the same.
  • Alternatively, a heart murmur in a cat may be dynamic, changing in intensity from one time to the next.

Murmurs are graded on a scale of one through six based on the intensity or loudness. A louder murmur indicates more turbulence and the loudest can be heard in multiple places on the cat. A softer murmur may only be heard in one place. It is important to know, however, that the grade of the heart murmur does not indicate the severity of the disease.

How to Handle Feline Heart Murmurs

The intensity of the heart murmur does not tell us whether the murmur is a result of serious disease or not. Instead, we have to rely on diagnostic testing to find out why the heart murmur is there.

In cats, heart murmurs are usually best evaluated with an echocardiogram, an ultrasonic examination of the heart. It allows the veterinarian to assess the heart muscle, the individual chambers of the heart, the valves of the heart, and other critical structures within the heart.

Though some cat owners elect to wait and do nothing other than observing their cat if she is otherwise acting normally, this may not a wise course of action. Cardiomyopathies (diseases of the heart muscle) and some of the other heart diseases associated with a heart murmur can develop severe and life-threatening signs very quickly. In some cases, even sudden death may occur.

An echocardiogram can allow an accurate diagnosis about whether the heart murmur is dangerous for your cat. In some cases, it may be found that the murmur is benign and not dangerous. However, the only way to know that for certain is with proper evaluation of the heart. That will also help put your mind at ease.

Be sure to thoroughly discuss your options with your vet. They will be able to direct you to the best course of action for the situation. The treatment options will vary depending on the actual cause of the murmur.

Please note: This article has been provided for informational purposes only. If your pet is showing any signs of illness, consult a veterinarian as quickly as possible.