Ebstein's Anomaly in Dogs

Ebstein's anomaly is the medical name given to a type of congenital heart defect in which the opening of the tricuspid valve (on the right side of the heart, between the right atrium and the right ventricle) is displaced toward the apex of the right ventricle of the heart. It is accompanied by various degrees of tricuspid insufficiency, or stenosis (abnormal narrowing in a blood vessel).

An abnormal accessory pathway may lead to rapid heart rhythms. It is very rare, but is occasionally encountered in dogs. A murmur can be heard with a stethoscope at a young age, though it can be much more difficult to hear it if there is stenosis. There is no breed or gender predilection.

The condition or disease described in this medical article can affect both dogs and cats. If you would like to learn more about how this disease affects cats, please visit this page in the PetMD health library.

Symptoms and Types

• Dogs with mild tricuspid insufficiency or stenosis will be asymptomatic (without symptoms)
• Dogs with moderate insufficiency, or stenosis, will often show an intolerance for exercise
• Dogs with severe insufficiency, or stenosis, will suffer congestive heart failure (CHF), with fluid in the chest or abdomen (swelling in the abdomen, or chest, may be observed)
• There may be some fatigue or dizziness associated with this condition, due to the increased pressure on the heart to function

Diagnosis

Your veterinarian will perform a thorough physical exam on your dog, including a chemical blood profile, a complete blood count, and a urinalysis. You will need to give a thorough history of your dog's health, including a background history of symptoms.

Your veterinarian will order an x-ray of the chest, and will look for evidence of right atrial and ventricular enlargement, as well as an enlarged kidney. Echocardiography can also be used to examine the heart and chest, by showing an ultrasound image of the size, motion and composition of the heart and surrounding structure. An electrocardiogram to measure the electrical activity and pressure within the heart, will be necessary for verifying a definitive diagnosis of Ebstein's anomaly.