Heart Murmurs in Cats

What is a heart murmur?
Anytime there is a cardiac disruption in blood flow, extra heart vibrations are the result. Sometimes these pulsations cause an audible noise. A feline heart murmur is usually detected during the course of a routine exam when the vet listens to your cat's heart. The murmur is heard as a whooshing or swishing sound during the normal cycle of the heartbeat.

Types and symptoms
Many conditions can cause a feline heart murmur. Some are serious and may be life-threatening. Others are not related to disease and may not affect the cat's health. Many characteristics define the kind of murmur and your vet is trained in identification. Owners can tell if congestive heart disease is a possibility if his/her cat shows coughing, weakness, or exercise intolerance. But, only a vet can be sure.

Causes
Structural heart defects often cause murmurs. The defect may be present at birth (congenital) or it may have been the result of a heart disease later in life.

Other causes
Feline heart murmurs may also be due to non-heart related causes such as fever or infection. Also, it may occur in cats that are pregnant, obese, or emaciated. In addition, low red blood cell levels (anemia), low protein levels in the blood (hypoproteinemia) or an enlarged thyroid gland that produces too much hormone (hyperthyroidism) can each cause feline heart murmurs. Once again, routine vet checks are important for early diagnosis.

Diagnosis
Diagnostic testing is necessary to identify a murmur and are best evaluated with an echocardiogram. An owner’s decision to wait and see what happens, without consulting a vet, is not a good choice because other diseases associated with a heart murmur may quickly develop into severe, life-threatening conditions.

Treatment
Depending on the cause of the murmur, treatment options vary. If benign, no treatment is necessary. Kittens with low grade murmurs, for example, may require little or no treatment and the murmur may resolve itself within six months. However, if the murmur is due to an underlying issue, Dr. Jessy in the Bredel Clinic at the HART Animal Center may recommend surgery, medication, a special diet, or some other type of specialized care. For an appointment, please call 301.387.7729.