Atrial Fibrillation in Cats

Atrial fibrillation is a very serious condition that is usually permanent and often fatal. It is more common in dogs than in cats. Although it may be a rare condition, it is still something to keep an eye out for.

Defining Atrial Fibrillation

This is an abnormality that causes a rapid rate of muscle contractions in the heart. It causes the normal electrical rates in the left and right atrium and the upper heart chambers to become unstable or lost. This in turn causes the muscles to flutter, which reduces the heart's ability to function properly.

This condition is most often a secondary result of an underlining heart problem, but it has been known to appear entirely on its own. Many cats who suffer from this condition will have congestive heart failure.


There are not many symptoms of this condition and they are not easy to catch unless you are paying close attention. The most common symptoms include:

  • Less willingness and tolerance for activities such as exercise
  • Abnormal heart rhythms
  • Fluid built up in the abdomen or chest, which can lead to congestive heart failure
  • Rapid heartbeat

The most important one to keep an eye out for is the sudden lack of willingness to play. Too many pet owners brush this off as their cat simply getting older and lazy, but sometimes it can be a serious indicator that something is amiss. If you notice this with your cat, try checking her heartbeat to see if it is rapid or abnormal.

Diagnosing Atrial Fibrillation

To properly diagnose this condition, your veterinarian will need to run a variety of tests. It is important that you give your cat's complete medical history to your veterinarian. Some of the tests that can be used to determine this condition include:

  • Electrocardiogram. This will allow the veterinarian to determine the exact rate and rhythm of your cat's heartbeat.
  • Echocardiogram. This is to determine if the atrial fibrillation is standing on its own or if there is an underlying heart condition.
  • Complete Physical. This will include listening to your cat's heartbeat with a stethoscope.


Treating this condition depends entirely on whether or not there is an underlying heart problem. If there is, the outcome will revolve around whether or not the underlying cause is treatable and how far along it has progressed.

There are three main goals in the treatment of this disease, which are to get the heart rate under control, to control the congestive heart failure if it is present and to slow down the rate at which the condition progresses. This can involve the use of medications, fluids and oxygen, along with a change of diet. Cats will often have to be hospitalized for at least a day or two.


There is no known prevention for this condition. Give your cat regular checkups and pay close attention to any symptoms she may display.