FELINE CARDIOMYOPATHY IS A SERIOUS DISEASE THAT CAN BE DIFFICULT TO DIAGNOSE IN ITS EARLY STAGES. OLDER CATS, ESPECIALLY MIDDLE-AGED MALES, ARE THE ONES THAT ARE MOST AT RISK.
Cardiomyopathy, which literally means “disease of the heart muscle,” is one of the most common problems to affect the feline heart.
Hypertrophic cardiomyopathy (HCM) is the most common form of feline cardiomyopathy.
In addition to not being able to pump enough blood, the heart of a cat affected by HCM can suffer other abnormalities. Blood clots can form in the upper chamber of the heart, the left atrium. Unable to empty properly into the left ventricle, the left atrium becomes enlarged with extra blood, which begins to sludge and then clot. The resulting “atrial clots” or pieces of them, might then be pushed into the cat’s bloodstream. The risk that a clot might lodge in a smaller blood vessel is great; one of the most common sites for such an event is the area where the aorta splits at its end to supply blood to each rear leg. When a clot lodges here, the cat becomes acutely paralyzed in one or both back legs. The condition is very painful and often results in death or euthanasia.
Another potential complication of HCM is that the added muscle mass of the heart can predispose a cat to an arrhythmia, an abnormal heartbeat pattern that can potentially cause sudden and unexpected death.
Detection can be very difficult, especially early in the course of disease when clinical signs are absent or subtle at best. Careful examination by a veterinarian might possibly reveal a rapid heart rate, perhaps accompanied by a heartbeat irregularity called a gallop rhythm.
Other form of heart murmurs might also suggest the need for a more extensive cardiology examination that could lead to a diagnosis of cardiomyopathy.
As the heart disease progresses, the signs of it become more dramatic. A cat might be presented to a veterinarian because he is having trouble breathing. Cats with heart failure often have difficulty breathing as the heart begins to fail and the lung tissue and/or chest cavity fills with fluid that seeps from the backed-up veins.
The most dramatic symptom of cardiomyopathy is the sudden death of a cat whose symptoms have gone undetected and whose illness is undiagnosed.
Abnormalities detected during a physical examination can arouse a veterinarian’s suspicion that cardiomyopathy exists, but a definitive diagnosis requires examination of the heart itself. Radiographs (X-rays) can demonstrate the “valentine” shape of the dilated heart of DCM.
An electrocardiograph (ECG) can be employed to detect whether any life-threatening cardiac arrhythmia exist.
Blood test may help identify impairment of major organs that has resulted from a lack of oxygen supply, or from clot formation. A urinalysis can detect concurrent urinary system disease, which may complicate therapy.
The treatment for cardiomyopathy depends on the form diagnosed and the state of disease. Therapy really does depend on the severity of the clinical signs, the body’s reaction to the disease, and the patient’s ability to compensate.
Older cats, especially those middle-aged males who are most at risk, may also successfully hide their symptoms until it’s too late to help them. Those cats whose caretakers are aware of the existence of cardiomyopathy and work with their veterinarian to assess their cat’s risk stand the best chance of surviving this significant heart disease when it does occur.