Dilated Cardiomyopathy of Dogs Fact File
Dilated cardiomyopathy (DCM) has been recognized in many breeds but seems more prevalent in certain breeds, a recent survey of 76 dogs with DCM indicated this condition to be most common in Great Danes (46%) followed by St.Bernhard (10%), Newfoundland (10%), Neapolatan mastiff (5%), Rottweiler (3%), Dougue de Bourdeux (3%), Boxer, Labrador, Leonberger, Collie, Dalmation, English Cocker Spaniel, GSD, Greyhound, Irish Wolfhound and mongrel (2% each). The exact aetiology of individual cases usually remains undetermined however, several factors have been proposed including genetic factors, nutritional deficiencies, metabolic disorders, immunological abnormalities, infectious diseases and drug toxicities.
In dogs familial DCM has been shown in a number of breeds; (Irish wolfhounds, boxers, dobermans, Newfoundlands, weimaraners) an autosomal dominant mode of inheritance is suspected, while in the Portugese Water Dog autosomal recessive transmission has been documented. It is likely that different breeds have different gene defects. A defect in the cytoskeletal gene dystrophin has been identified as a cause of X-linked DCM in German shorthaired pointers which also have concurrent skeletal myopathy.
Nutritional myopathies causing myocardial hypokinesis (decreased motor activity) i.e. carnatine and taurine deficiencies have been documented in dogs, cats and humans. Metabollic disorders which have been associated with DCM include hypothyroidism, diabetes mellitus and phaeochromocytoma. Cardiotoxin agents which induce tachycardia with chamber dilatation and CHF include doxirubicin and other antineoplastic agents, ethanol, cobalt, lead, catecholamines, histamine, methylxanthines and vitamin D.