Dilated Cardiomyopathy initially starts with the degeneration of the heart muscle which becomes weaker and thinner. The heart, especially on the left ventricle should have a thick muscular wall, but over time this muscle becomes thinner leaving less wall and leave more space within the heart.

As this happens, the heart loses its ability to pump blood around the dog’s body. The blood congests in the heart, which causes the heart muscle to stretch even thinner and this stretching causes the large, dilated appearance which is where its name comes from.

Some dogs may develop a heart murmur if the heart valves become stretched enough to cause a leak. The stretched heart muscle may cause some dogs to develop an unusual heart rhythm.

According to the VCA animal hospitals ( “Dilated cardiomyopathy is the most common cause of heart failure in certain large breed dogs. These include boxer dogs, Doberman Pinchers, Great Danes, Irish Wolfhounds, Newfoundland, standard and giant Schnauzers and Saint Bernards.