Feline Cardiomyopathy
The word cardiomyopathy means heart muscle disease.
Cardio=heart
Myo=muscle
Pathy=disease
There are three different cardiomyopathies that affect cats today with the most common being hypertrophic cardiomyopathy (HCM). Cats with HCM have thicker than normal heart walls. The fist sign of HCM is often your veterinarian reporting that your cat has developed a heart murmur. This is often shocking to owners because cats with HCM often show no signs until the later stages of the disease. The first signs that are usually noticed is difficulty breathing this is caused by fluid building up in the lungs or chest, sudden and very painful hindlimb or forelimb weakness or paralysis as a result of a blood clot blocking blood flow to these limbs, or sudden death. Signs of HCM can be as subtle as lack of appetite, increased respirations while resting, and weight loss. Treatment of HCM often consists of an ACE inhibitor such as benazepril. If there is fluid in the chest a diuretic such as furosemide may be prescribed and in some this fluid needs to be manually drained by a veterinarian.
Prognosis in cats with HCM is not easy to predict. Many cats live a long time with out ever needing medication for this condition, while others will die suddenly or progress to develop congestive heart failure. In terms of discomfort and frustration the worst outcome is a clot being sent into limbs or other organs. Veterinary cardiologists are available for consultation on cats with HCM and along with your veterinarian is the best guide to diagnosis and treatment of HCM in cats.
Dilated cardiomyopathy used to be a much more common disease in cats. This lasted until the 1980s when it was discovered that insufficient taurine levels in feline diets were the cause of most cases of dilated cardiomyopathy. Taurine is an amino acid that cats cannot make on their own this is one reason that home cooked foods for cats must be balanced for what the cat needs. In dilated cardiomyopathy the heart muscle weakens and the heart muscle becomes very large and contracts weakly. In cases of dilated cardiomyopathy taurine levels can be assessed with a blood test and your veterinarian will look into your cat’s eye to look for central retinal degeneration, which can be another sign of taurine deficiency. Most cats that recover from taurine deficiency can recover heart function with in 4 to 6 months, but symptoms of heart failure must be aggressively managed during this period with the same techniques listed for HCM.
Restricted and unclassified cardiomyopathies are less well understood, These forms also require diagnosis from echocardiogram but there are no specific known causes or treatments.