Feline cardiomyopathy is a truly insidious heart disease. It is seen more often in purebreds than in mixed-breed cats. Often no previous history of distress exists, and the owner discovers his or her apparently healthy cat dead with no outward appearance of the cause. On postmortem examination, the heart is found to have undergone significant changes, expecially thickening of the heart muscle. This causes loss of elasticity, making it nearly impossible for the heart to expand and contract.
A cat may show few or no physical signs of the disease until it is in an advanced state. Occasionally the disease is discovered when a concerned owner notices a change in a cat’s breathing or activity level. Sometimes the heart sounds are audibly abnormal when checked with a stethoscope. Chest radiographs and an echocardiogram are the best diagnostic tools, but they are not usually included in an annual physical examination because of the cost. For purebred cats, however, at least an ECG would be advisable during checkups. Early diagnosis would allow time for management of the disease.