What is DCM?

Dilated cardiomyopathy is a disease of the heart muscle which results in poor contraction. DCM is most commonly an inherited condition in large-breed dogs such as the Doberman, Great Dane, and Irish Wolfhound, and can affect middle-aged or older dogs. Recently, certain diets have been linked to development in DCM in dogs. Cats can rarely develop DCM.

In the early stages of disease, dogs may have no symptoms. Some dogs have a heart murmur or irregular rhythm, but other dogs may sound normal when their chest is ausculted with a stethoscope. Over time, the poorly functioning heart causes a backup of blood. If the left heart fails, fluid can back up into the lungs and cause coughing or trouble breathing. If the right heart fails, fluid can pool in the belly or around the lungs. DCM can also cause irregular heart rhythms that result in fainting or, if severe, sudden death.

What treatments are available for DCM?

In the asymptomatic phase, medication may help delay progression to congestive heart failure. An appointment with a cardiologist is recommended to determine if and when treatment is necessary.

In the early stages of disease, dogs with DCM may remain asymptomatic for years. Once the disease progresses to severe DCM or congestive heart failure, lifelong medications are required. If your dog accumulates fluid in the belly, periodic taps (removal of fluid with a needle) may be required. Unfortunately, unless a diet problem is responsible, the disease cannot be cured, but on average dogs can have good quality of life for 6-12 months.

What should I monitor at home?

It is important to become familiar with your pet’s normal sleeping respiratory rate. Often, the first indication of development of heart failure is an increase in the breathing rate when sleeping, and early detection of heart failure can help avoid a hospital stay. Your pet’s respiratory rate should be less than 40 breaths per minute when sleeping. However, any consistent or progressive elevation from your pet’s baseline rate should be cause to alert a veterinarian. There are several free iphone aps (ex. Cardalis) which can help keep track of respiratory rates.

You should also monitor for cough, lethargy, fainting, abdominal distension, or decreased appetite, and contact a veterinarian with any concerns.