Canine dilated cardiomyopathy. Part 2: manifestations and treatment of clinical DCM

Abstract

Background: Dilated cardiomyopathy (DCM) is the second most common heart disease in dogs, and is more common in large or giant breeds. Physical examination may be unremarkable before the development of clinical signs such as congestive heart failure (CHF), syncopal episodes due to arrhythmias or impaired cardiac output. Different breeds may have different manifestations of DCM, with atrial fibrillation being common in Irish wolfhounds, and ventricular arrhythmias being common in dobermanns. Arrhythmias may coexist or precede development of typical echocardiographic changes of DCM. Idiopathic DCM is believed to have a genetic basis but there can be other causes of the echocardiographic changes that are typical in DCM (called a DCM phenotype), such as nutritional or secondary to primary arrhythmias (tachycardia-induced cardiomyopathy), which need to be excluded. Treatment is palliative and directed at identifying and treating the primary cause of a DCM phenotype, treating CHF or significant arrhythmias. This is the second article in a two-part series on DCM. Part 1, which was published in the November issue of In Practice, focused on the screening, diagnosis and management of preclinical DCM.

Aim of the article: The aim of this article is to update the veterinary surgeon with presentations and manifestations of dogs with DCM, to exclude contributing factors mimicking DCM and to successfully manage affected patients.