Dilated Cardiomyopathy in Dogs

Dilated Cardiomyopathy or DCM in dogs is a disease that affects the heart muscles and results in weak contractions of the heart. It’s very common in dogs and causes congestive heart failure.

DCM is a disease that generally affects large and giant dog breeds like Doberman pinschers, Irish wolfhounds, boxers, Afghan hounds, Great Danes, Dalmatians and Saint Bernards. Apart from these breeds medium sized breeds such as cocker spaniels and male dogs in particular can get affected by this disease. Since cardiomyopathy can be fatal it’s important to seek medical help in time.

Dilated Cardiomyopathy in Dogs  

DCM is a disease in which the heart muscles get dilated or enlarged. The pumping ability of the heart is also adversely affected because the heart’s contractions are weakened. The chamber of the heart that’s most affected is the left ventricle. However, in advanced cases of the disease, all 4 chambers of the heart get dilated.

The thick muscle wall of the left ventricle of the heart becomes thinner as a result of the disease. This thin wall is stretched by the pressure of the blood inside the ventricle thus resulting in a very large left ventricle. DCM is characterized by thin heart walls and a larger than normal left ventricle.

Symptoms of Dilated Cardiomyopathy in Dogs:

  • Coughing
  • Shortness of breath
  • Distension of the abdomen
  • Loss of appetite
  • Loss of weight
  • Lethargy
  • Intolerance to exercise
  • Irregular heart rhythm
  • Increased heart rate
  • Pale gums
  • Rapid breathing
  • Difficulty in breathing
  • Weakness
  • Death
  • Leakage of blood from the blood vessels into the lungs thus causing pulmonary edema and failure of the left side of the heart 
  • Leakage of blood from the blood vessels into the chest and abdominal cavities causing failure of the right side of the heart

Diagnosis of DCM in Dogs

The tests that can conclusively diagnose DCM and rule out other diseases include a complete medical history, a physical examination, auscultation, chest X-rays, an electrocardiogram, arterial blood pressure, complete blood count, urine tests, echocardiogram and serum biochemistries.

Blood and urine tests can point out any disorders that can affect heart function. Chest X-rays give a view of the size and shape of the heart and give a picture of the lungs.

Any enlargement of the heart can be spotted in an X-ray, an ECG or an EKG. The echocardiogram uses sound waves that bounce off the structure of the heart to determine the size of the heart and each of its chambers. The thickness of the heart walls can also be determined by this test along with the strength of the contractions.

Treatment of DCM in Dogs

Diuretics such as Furosemide are administered to stimulate the kidneys and remove extra fluid from the body. A venodilator such as Nitroglycerin is administered to dilate the veins and decrease the amount of blood that enters the heart. Vasodilators are administered as they can dilate the blood vessels for longer durations than venodilators. Digitalis regulates the release of hormones, strengthens each contraction and reduces the heart rate.

Enzyme blockers are also administered to block the compensation system that’s out of control. Besides this, amino acids such as carnitine and taurine are also administered to improve heart function.

The prognosis for dogs with DCM isn’t very good and you should take your pet to the vet regularly to monitor his condition. Stress and physical activity should also be kept at a minimum.