This condition the heart is enlarged and compensatory mechanisms are acting to maintain blood flow. The dog will initially have no clinical symptoms but will eventually exhibit lethargy, will tire easily (heart can't pump enough blood), start coughing (fluid in lungs), etc. Basically the symptoms of congestive heart failure.

There is no cure for dilated cardiomyopathybut there are treatments that will improve cardiac function which will deninish the clinical symptoms. The typical treatment consists ofenalapril (angiotensin converting enzyme inhibitor), lasix (diuretic),and digoxin (improves the contractility of the heart, i.e. functions better). The treatment, in addition to lessening the clinical manifestations of the disease, may prolong the dog's life. Since cardiomyapathy is a progressive disease. Treatment prior to the appearance of clinical symptoms may slow down the progression and increase the dog's life expectancy.

Increased heart rate

This happens because you do not have full function of an area of the heart muscle. This make the none affected area work harder increasing heart rate.

Hereditary

Cardiomyopathy can be passed down through the generations.