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Dilated Cardiomyopathy: DCM in Dogs

DCM is a heart condition that can lead to CHF in dogs.

Dilated cardiomyopathy in dogs occurs when the heart muscle is too weak to pump adequate amounts of blood—and therefore, oxygen—to all the body's tissues. It is a condition of the heart muscle itself.

As the heart's walls become thinner and floppier, the heart enlarges and becomes less effective. Eventually, congestive heart failure develops. That is the state in which the heart can't keep up with the oxygen demands of the body. Fluid begins to build up in the lungs, chest, or abdomen.

Dogs with DCM can also develop life-threatening heart arrhythmias (irregular heart rates).

What Causes DCM in Dogs?

DCM is suspected to be a genetically induced condition. It's the most common cause of heart disease in large breed dogs, especially Dobermans, Irish wolfhounds, Great Danes, and Saint Bernards, but is also seen in cocker spaniels.

Nutritional deficiencies in taurine or carnitine have been known to cause the condition in some breeds.

Boxer cardiomyopathy is a type of DCM caused by a heart arrhythmia.

DCM is currently being recorded in breeds it's not usually been seen in, and the FDA has identified several grain-free diets that seem to be associated with it.

Signs of DCM in Dogs

The signs of DCM in dogs may include:

  • Rapid or labored breathing
  • Coughing
  • Weight loss
  • Enlarged abdomen due to ascites
  • Decreased appetite
  • Exercise intolerance
  • Weakness
  • Restless sleep
  • Lethargy
  • Syncope (fainting)
  • Collapse
  • Sudden death

Some dogs do not show any signs of DCM but then quite suddenly seem to develop signs of CHF, in a matter of hours. Those dogs had developing disease that came on slowly, allowing the dog to compensate until it was suddenly too much to handle.

Diagnosis of DCM in Dogs

Blood work and urinalysis of dogs with DCM are usually normal unless severe heart failure has set in.

X-rays will show a generally enlarged heart. If CHF is underway, abnormal fluid may be seen in the lung fields. Ascites (abnormal abdominal fluid) may be seen on x-rays.

Echocardiography is the best way to diagnose DCM in dogs as well as determine its stage. The veterinarian can measure the heart's walls and the blood flow.

Treatment of DCM in Dogs

When a dog is diagnosed with DCM, some of the following medications may be required depending on the individual's state:

  • Diuretics to remove extra fluid from the body
  • Heart medications that lower blood pressure or increase heart muscle contractions to make pumping easier
  • Medications that dilate arteries or veins to relieve the workload on the heart
  • Bronchodilators to ease breathing
  • Pimobendin (Vetmedin), a drug that improves the strength of the heart muscle
  • Anti-arrhythmic medications to normalize the heart rhythm

Dogs will be monitored through x-rays or echocardiograms during treatment, so medications can be adjusted as needed.

The prognosis for dogs with DCM is poor long-term. Sudden death is common.

You May Also Like These Articles:

Congestive Heart Failure: CHF in Dogs

Boxer Cardiomyopathy: Arrhythmogenic Right Ventricular Cardiomyopathy

Heart Disease in Dogs

Ascites in Dogs

Pulmonary Edema in Dogs

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