Health & Testing

Genetic Heart Disease in Dogs: An Overview for Breeders and Buyers

Cardiac disease is a major cause of mortality in dogs. Here's the overview of major inherited heart conditions across breeds — and what testing catches them.

April 28, 2024 · 5 min read

Mitral Valve Disease (MVD)

The most common cardiac disease in dogs overall — especially in small breeds. MVD causes progressive degeneration of the mitral valve, leading to murmur and eventually heart failure. Cavalier King Charles Spaniels have extraordinary prevalence. Requires cardiologist auscultation for assessment — not DNA testable. The MVD Breeding Protocol requires cardiac clearance of both parents before breeding.

Dilated Cardiomyopathy (DCM)

DCM causes the heart muscle to dilate and weaken, reducing pumping efficiency. Common in Dobermans, Great Danes, Irish Wolfhounds, and Boxers. A DNA test for the PDK4 gene mutation exists for Dobermans. Other large breed DCM has suspected but not yet fully characterized genetic components. Regular echocardiography is recommended for at-risk breeds.

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)

Also called Boxer Cardiomyopathy. Affects primarily Boxers. Causes irregular heart rhythms (arrhythmias) and sudden cardiac death. A DNA test for the Striatin mutation is available — but ARVC can occur in Striatin-negative Boxers, so both DNA testing and Holter monitor evaluation are recommended.

Subvalvular Aortic Stenosis (SAS)

A structural obstruction below the aortic valve, common in Golden Retrievers, Rottweilers, and Newfoundlands. Not yet fully DNA testable. Requires echocardiographic screening by a cardiologist. Affected dogs should not be bred.