Treatment Considerations for Feline Cardiomyopathy

Feline cardiomyopathy is a cat heart disease, often fatal, in which the heart walls change shape by stretching or thickening, making it difficult for the heart to work properly. In the past one of the more common versions was dilated cardiomyopathy in cat populations resulting from a taurine deficiency; however, with almost all major brands of cat food including taurine as one of its ingredients, it is rarely seen today. The heart muscle stretches and weakens with this version of the disease.

Feline heart disease has a number of causes. Often it is genetic, although possessing the gene that causes cardiomyopathy does not necessarily guarantee developing the disease. It can skip generations. Chemicals, poisons, infections and hyperthyroidism can also cause cardiomyopathy. The most common form, feline hypertrophic cardiomyopathy, involves the thickening of the cat heart muscles resulting in a decrease in volume of blood being pumped through the heart.

Symptoms of Feline Cardiomyopathy

Symptoms for cardiomyopathy are rapid or trouble breathing, weight loss, decreased appetite, lethargy, fatigue, fainting spells and paralyzed or weak legs resulting from formations of blood clots in the arteries to the legs. Some of these symptoms develop gradually and some develop rapidly and can lead to death if not treated quickly. X-rays, EKG and ultrasound of the heart will confirm the disease.

Treating Cardiomyopathy by Type and Severity

Depending on the type of cardiomyopathy and the severity, different medications can improve heart function but not cure the disease especially if it develops into heart failure. The average life span is about 6 months, although some cats have lived to 3 to 4 years.

Treatment includes:
  • Diuretics: Usually frusemide is used to remove fluid from around the lungs; however, renal function must be monitored. Pleural fluid can be drained from the lung wall with a needle or catheter.
  • Beta Blockers: Usually atenolol and metoprolol, which help improve the function of the left ventricle thereby, increasing the volume of blood flowing to the lungs and decreasing pulmonary edema. Beta blockers slow down the heart rate allowing the heart to completely fill before contracting.
  • ACE Inhibitors: Usually benazepril and enalapril, which improve heart function causing vasodilation and thus reducing the heart's workload.
  • Calcium Channel Blockers: Usually diltiazem, which also helps improve heart function by reducing myocardial oxygen consumption and heart rate by helping the heart muscle to relax to allow for more room for the ventricles to fill completely with blood before contracting.
  • Treating underlying problems: Using amlodipine to reduce blood pressure in cases of hypertension and treating hyperthyroidism.
  • Reducing the risk of thromboembolism: Usually clopidogrel (platelet inhibitor) or heparin (blood clotting inhibitor) is used in low doses since an overdose can be fatal.

Cardiomyopathy cannot be cured, except when hyperthyroid or taurine deficiency is involved.