Cardiomyopathy (CM) is a common, insidious, slowly progressive disease of the heart muscle that affects both sexes in dogs and cats. The disease progresses slowly for some time before symptoms become apparent. Once symptoms of congestive heart failure (CHF) become apparent, survival time may only be a matter of months. A frightening aspect of this disease is the fact that in 25 to 30% of affected dogs, sudden death is the first symptom.

PREVALENCE. . . . .
CM occurs in most large breeds with the highest incidence being in Dobermans and Boxers. Several studies have found that approximately 20 to 30% of Dobermans have probable markers (including echocardiographic abnormalities or heart rhythm disturbances) on their first examination.

CAUSE. . . . .
The cause is poorly understood, but a genetic component is suspected. Although nutritional deficiencies, including taurine and carnitine, have occasionally been demonstrated to cause CM in some cases, known deficiencies do not appear to be the sole inciting cause. In some breeds, viral infection can cause CM but this has not been demonstrated in Dobermans. In dogs there are strong familial tendencies. CM in cats is often secondary to hyperthyroidism.

IDENTIFICATION. . . . .
Overt congestive heart failure represents the end stage of disease and is difficult to treat. Survival times are generally short. Early detection is important in maximizing treatment options. Annual ECG screening is recommended for older large breed dogs. Boxers and Dobermans should be screened yearly beginning at 1-2 years of age. If abnormalities are found an echocardiogram and other tests are indicted.

TREATMENT. . . . .
The disease may be treated with vasodilators, diuretics, digoxin or beta-blockers based on the individual’s needs.