Screening for DCM in Dobermans

Dilated cardiomyopathy (DCM) is a disease of the myocardium associated with dilatation and impaired contraction of the ventricles. In the dog, it primarily affects large and giant breeds; the Doberman pinscher is one of the most frequently affected. Extensive remodeling, in the form of a loss of collagen tethers, increased collagen synthesis, and alterations in collagen cross-links, occurs in the diseased myocardium. Changes in the collagenous matrix are also present in apparently normal Dobermans. Stage I DCM is characterized by a morphologically and electrically normal heart and no clinical signs of heart disease; stage II by evidence of morphologic or electrical derangement in the absence of clinical signs of heart disease; and stage III by clinical signs of heart failure. A prospective study based on a cohort of European Doberman pinschers evaluated the prevalence of DCM among various age groups. The study population consisted of 412 (54.9% female, 45.1% male) client-owned Doberman pinschers that were selected according to inclusion and exclusion criteria from a longitudinal cohort study. Each dog was assessed by 5-minute electrocardiography (ECG), 24-hour ECG (Holter) monitoring, and echocardiography at each examination. The cumulative prevalence of cardiomyopathy was 58.2%, calculated from all dogs with cardiomyopathy (independent of age) compared with healthy Doberman pinschers older than 7 years. There was an equal sex distribution, but male dogs showed earlier echocardiographic changes than females. On the basis of the study findings, the author recommends yearly screening of Dobermans for DCM by Holter examination and echocardiography starting at 2 years of age.

Commentary: This relatively large study was designed to define the prevalence of DCM in each of 5 age groups of Doberman pinschers from Germany and surrounding countries. Using previously established diagnostic criteria, dogs were examined using both Holter (24-hour ECG) monitoring and standard echocardiographic measurements. The authors found a high (58%) cumulative prevalence of the disease in this population. Males and females received a diagnosis of DCM with equal frequency, although males showed clinical evidence of the disease more often. The prevalence of DCM increased with age (highest in 6–8 years and over 8 years, repectively). These findings are consistent with previous genetic and clinical investigations performed in studies of North American Doberman populations. The results of these studies have practical implications for screening Dobermans for DCM: 1) both echocardiography and Holter monitoring have value in screening (if resources are limited, Holter monitoring is a more sensitive screening tool); 2) annual screening should begin at 2 years of age; and 3) both male and females should be screened.

Prevalence of dilated cardiomyopathy in Doberman pinschers in various age groups. Wess G, Schulze A, Butz V, et al. J VET INTERN MED 24:533-538, 2010.