DCM in Dobermans

Dilated cardiomyopathy (DCM) is a very common form of heart disease in dogs. Only degenerative valve disease (also called mitral valve disease or endocardiosis or mitral insufficiency) and in some places heartworm disease are more common. It was not until the 1970s, when echocardiography began to be performed in veterinary institutions, that dilated cardiomyopathy could be diagnosed non-invasively with any certain degree of accuracy. The reported prevalence in dogs is approximately 0.5%.

Based upon a national database of dogs presented to veterinary schools in North America, we know that 5.8% of the Doberman Pinschers that were seen at a school had DCM, 5.6% of the Irish Wolfhounds presented had DCM. 3.9% of the Great Danes, 3.4 percent of the Boxers and 2.6% of the St. Bernards. In general, the dogs are middle age (4-10 years of age) with Males being over-represented (2:1). 70-80% of the Dobermans with congestive heart failure due to DCM are male and in a recent paper describing the disease in Dalmatians, all of the affected animals were male. This does not mean that female dogs are not affected by DCM, on the contrary, Dr. O’Grady at the University of Guelph found no sex predilection for Dobermans with subclinical (Asymptomatic or occult) DCM.

Familial and Genetic Influences

The general feeling is that most cases of DCM have a familial or genetic basis. This is based upon the observation of a higher prevalence in purebred dogs, in certain breeds and within certain families.

There are also strong indications in other breeds such as the Doberman, where DCM can affect more than 50 percent of family members. In Portuguese Water Dogs DCM appears to be autosomal recessive and in English Cocker Spaniels it is associated with a particular immune deficit. An autosomal dominant mode of transmission has been proposed for the Newfoundlands with DCM.

Nutritional Influences

Taurine In the late 1980s taurine deficiency was recognized as the cause of dilated cardiomyopathy in the majority of cats with DCM. Since then investigators in the field have found a relationship between taurine deficiency and DCM in certain breeds such as Cocker Spaniels, Golden Retrievers and Newfoundlands.

Dogs with preclinical disease may go several years without clinical signs, so the diagnosis does not imply immediate risk of morbidity or mortality. Once the dogs become symptomatic, standard therapies for treatment of the heart failure and/or cardiac arrhythmias should be instituted. Nonetheless, the prognosis for Dobermans with DCM is poor.

Unless a reversible underlying cause is identified (e.g. taurine deficiency, primary tachyarrhythmia), the prognosis for DCM is often poor once overt clinical disease (CHF) develops, with most survival times being in months. The median survival time in a large retrospective study with mostly clinically significant dogs was 19 weeks, with one-year and two-year survival rates of 28% and 14%, respectively. In the Doberman, one-year survival rates of 10% or less have been reported, and treatment with triple therapy yielded a median survival time of 130 days.

Treatment of dilated cardiomyopathy is quite variable and depends upon the severity of the problem as well as the predominating symptom (e.g. fainting vs. coughing). The treatment may include things such as a moderately sodium restricted diet, diuretics, cardiac glycosides, nitrates, ACE inhibitors and various antiarrhythmic agents. Taurine and carnitine may also be added.