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Boxer Cardiomyopathy: Arrhythmogenic Right Ventricular Cardiomyopathy

Boxer cardiomyopathy is a heart condition in boxer lines.

Boxer cardiomyopathy is a heart condition that is genetically based in some boxer dogs. It causes heart arrhythmias, which are abnormal heartbeats, that start in the ventricles (bottom heart chambers). Additionally, the condition can result in dysfunction of the heart muscle, congestive heart failure, and sometimes sudden death.

The exact cause of boxer cardiomyopathy isn't known, but it is likely to have a genetic basis.

Signs of Boxer Cardiomyopathy

Most of the time, boxers are between four and eight years old when boxer cardiomyopathy is diagnosed, but they can be any age.

The signs of the condition vary widely based on how functional the heart muscle is and can include:

  • Syncope (fainting)
  • Collapse
  • Exercise intolerance
  • Sudden death
  • Irregular heart rate
  • Heart murmur

For many dogs, the first sign they have the condition is, unfortunately, sudden death.

Diagnosis of Boxer Cardiomyopathy

Chest x-rays of a dog with boxer cardiomyopathy are often normal unless the heart muscle has become dysfunctional. Then, the heart may be enlarged. If the heart has failed, congestive heart failure may be evident on the x-rays as fluid in the chest cavity. The same is the case for echocardiography.

An electrocardiogram done on a dog with the condition may be normal unless the arrhythmias happen to occur while the test is being done. VPCs (ventricular premature complexes) are the hallmark flag of the condition, and they may be caught on an ECG.

A continuous ECG done with a Holter monitor is more likely to be successful at catching VPCs or ventricular tachycardia to help with diagnosis.

Treatment of Boxer Cardiomyopathy

If the dog has congestive heart failure, that should be treated aggressively. Some dogs require hospitalization. Otherwise, activity should be restricted because exercise makes the dangerous heart arrhythmia worse.

Atenolol may be prescribed to help control the arrhythmia.

Diuretics are used when congestive heart failure has been diagnosed, and medications that open the blood vessels (vasodilators like Enalapril) can be helpful too.

Affected boxer dogs should not be used for breeding.

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