Hypertrophic cardiomyopathy is an abnormal thickening (hypertrophy) of the heart muscle of cats. The thickening causes improper filling and impaired pumping of the heart, as well as abnormal heart rhythm. These changes result in difficult breathing and fluid accumulation in the lungs. Lack of appetite and vomiting often occur 1 to 2 days before breathing difficulties appear. In some cases, blood clots develop and may cause paralysis of one or more legs or sudden death.
The disease is most common in domestic shorthair cats, followed by domestic long hairs. Persian cats may be predisposed to the disease but Siamese, Abyssinians, and Burmese breeds are less frequently involved. Middle-aged male cats are most frequently affected.
Important Points in Treatment
1. Hypertrophic cardiomyopathy is a very serious disease. The prognosis (medical forecast) is guarded to good, depending on the response to treatment and development of abnormal heart rhythms or blood clots.