Mitral valve disease and dilated cardiomyopathy in canines

Canine heart disease is commonly seen in veterinary practice. Presentations that veterinary nurses might recognise range from the healthy dog that appears for annual vaccination with a heart murmur, to a patient that is admitted with a concurrent problem, such as cruciate surgery, or the patient that presents with congestive heart failure (CHF), which can be either acute or chronic.

Heart disease in dogs can have different origins, whether it is present from birth (congenital), develops at a later age (acquired) or is the result of an arrhythmia (arrhythmogenic). This article will focus on the most common forms of acquired heart disease seen in veterinary practice:

MVD has been shown to account for up to 70% of canine cardiac disease in veterinary practice (Det-weiler and Patterson, 1965; Häggström et al, 2004; Borgarelli and Häggström, 2010). MVD is characterised as a progressive disease, with a classic leftsided apical heart murmur, and is often seen in smaller breeds of dog. DCM is a myocardial disease characterised by ventricular dilatation, seen in medium- to large-breed dogs. Over time, the ventricle walls become unable to relax and contract properly, thereby reducing cardiac output. A diagnosis of DCM can be more challenging because it can have a primary myocardial origin, or can be the result of secondary diseases, such as nutritional or hormonal deficiencies.