There are 2 common types of heart disease we see in dogs on a regular basis. Mitral Valve Disease primarily in smaller dogs and Dilated Cardiomyopathy primarily in larger dogs. Dilated Cardiomyopathy Dilated cardiomyopathy means that the heart muscle becomes unable to pump properly. The pressure of the blood inside the heart then allows this weakened heart muscle to stretch, resulting in a much larger left ventricular chamber. Therefore, the two characteristics of dilated ca