What is a heart murmur?

A heart murmur is an abnormal sound that a veterinarian hears when listening to your pet’s heart through a stethoscope during a physical exam. Normally, we can hear two distinct normal heart sounds. When your vet hears an additional “whooshing” sound in between normal heart sounds, this is known as a heart murmur.

Learning that your dog or cat has a heart murmur or irregular heartbeat can be frightening for any animal owner. However, heart murmurs may be benign or harmless and may go away on their own, particularly in puppies and kittens. Some may reflect an early stage heart disease. Some may indicate a more serious cardiac condition.

However, unless clinical signs are present (see below), the presence of a heart murmur on its own does not warrant initiating cardiac treatments. The only way to know the extent of your pet’s condition is to perform additional diagnostic testing and determine the cause of the murmur and the severity of the heart disease, should your pet be diagnosed with one.