Dear Doctor: “My cat has a heart murmur”
Q. My veterinarian told me my kitten has a heart murmur. Does that mean he is going to have a lifetime of heart disease, with me shuttling him back and forth to the doctor?
Dear Ms. Tillinghast,
A. A murmur heard with a stethoscope in an adult cat might very well (but not always) signify heart disease, and follow-up tests are in order. The good news on that front is that if heart disease is diagnosed, it can often be effectively treated, with the cat having many wonderful years ahead.
With a kitten, the chances that a murmur indicates heart disease are much lower. Many kittens have what is known as an “innocent” murmur that they outgrow; it is very common for a kitten to have a soft murmur in the first months of life.
Murmurs are graded on a scale of 1 to 6 for loudness or intensity. The higher the number, the greater the blood flow turbulence somewhere in the heart or in the large vessels leading away from the heart. If your kitten has a grade 2 or lower, you can very reasonably choose to hold off on any further testing and just wait until the veterinarian listens to your pet’s heart closer to a year of age. The chances are high that it will not have worsened, and will very possibly have disappeared.