Skip to main content


Hypertrophic cardiomyopathy and Hypertrophic obstructive cardiomyopathy

Published: 11/13/2019

Check out this overview from Simon Swift MA VetMB CertSAC DipECVIM-CA (Cardiology) MRCVS and Liz Bode BVSc PhD DipECVIM-CA (Cardiology) MRCVS for Vetlexicon’s Canis service.

Hypertrophic cardiomyopathy (HCM) and hypertrophic obstructive cardiomyopathy (HOCM) are rare diseases in the dog, however HOCM has been observed in Pointers and Terriers and has been suggested to be predisposed, although most cases are sporadic. There are too few cases in the UK to allow breed predilections to be identified.
The disease is characterized by an asymmetrically thick left ventricle with a normal to small left ventricular chamber. The increased wall thickness decreases the afterload and results in a stiff chamber. Clinical signs include a systolic heart murmur over left base or apex, often exacerbated at exercise or by use of short acting agents that increase contractility or reduce afterload. Arrhythmia and gallop rhythm may also be noted. However, some may show no clinical signs.

ECG 3rd degree heart bloc
Sudden death is possible due to ventricular arrhythmias, and congestive heart failure can develop at a variety of ages. However, survival to at least middle age without clinical signs has been reported, and the prognosis for HOCM in young dogs is good.
With adequate preparation and understanding of the unique physiologic and anatomic differences involved, anesthetists can provide excellent care for pediatric patients. Learn to describe the risks associated with the administration of anesthetic agents to a pediatric patient, based on the physiology and pharmacology as related these patients, as well as some basic practices that help to minimize these risks.