Tricuspid valve dysplasia (TVD) is a congenital heart defect resulting in malformation of the right atrioventricular valve, known as the tricuspid valve. TVD can occur in both dogs and cats and has been proven to be genetic in Labrador Retrievers. The tricuspid valve separates the right atrium (upper chamber) from the right ventricle (lower chamber) and allows blood to flow in one direction from the right atrium to the right ventricle. The most common consequence of TVD is regurgitation (backflow) of blood from the right ventricle into the right atrium resulting in extra blood in the right heart chambers¬¬¬. With time, the right heart muscles will stretch to accommodate the extra volume. When stretching is at its limit, blood may back up and cause fluid accumulation in the abdomen or rarely around the lungs.

Tricuspid valve dysplasia typically results in an identifiable murmur; however, definitive diagnosis requires diagnostic tests such electrocardiography (ECG), radiographs (x-rays), and an echocardiogram (ultrasound of the heart). These tests will help in determining severity and are typically repeated to monitor overall progression.

Progression and prognosis depends on the severity of the malformation and resultant regurgitation. Mild changes may results in a normal lifespan with no complications. However, animals with severe changes are more likely to develop complications including congestive heart failure, arrhythmias (abnormal heart beats) or severe exercise intolerance. Surgical repair of the valve is rarely performed and medical management is usually only instituted after clinical signs develop. The overall goal of therapy is to improve the length and quality of life with medications and periodic centeses (fluid removal using a needle) if or when needed. Multiple drugs can be used depending on your pet’s needs and most of the drugs will need to be continued throughout his/her life. Routine reevaluation of your pet is needed in order to provide optimal care.

If your pet has been diagnosed with TVD, it will be important to monitor for signs of progression at home. Things to monitor include, but are not limited to: weakness/collapse episodes, distension of the abdomen, difficulty breathing (increased rate or effort), and a decrease in appetite.