HCM, or hypertrophic cardiomyopathy, is a confusing and frustrating disease to understand. Stated basically, it is a common heart disease found in cats of all breeds and backgrounds where the left ventricle becomes enlarged (thickened). Cats can appear healthy (asymptomatic) or they can show signs of the disease which require an echocardiogram to give an accurate diagnosis. The difficult part of this disease is that there is no genetic test available to determine if a cat is a carrier. So a breeder, such as myself, scans their cats every year or two years to monitor their cat’s heart. Maybe the scan is normal for the first two or three scans – so we keep using that cat in our breeding program, believing they are negative for HCM. Then suddenly the forth or fifth scan shows signs of HCM. We have inadvertently “passed” HCM on to another generation of offspring without knowing it. My point is this – just because an adult cat is scanning negative for HCM does not guarantee the cat will never develop HCM in its lifetime, or that its kittens will not develop the disease. These are living creatures, and just like people, there is no “lifetime guarantee”.
How is HCM diagnosed?
HCM is diagnosed using ultrasound of the heart – an echocardiogram. Echocardiography is a good way to detect moderate to severely affected cats. However, it may not always detect mildly affected cats where changes in the heart can be minimal.