You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Description
The tricuspid valve lies between the right atrium and right ventricle chambers of the heart. It is one of the so-called atrioventricular valves. It consists of a fibrous ring at the junction between the atrium and the ventricle with cusps (2 in the dog). It is a one-way valve that does not allow blood to pass back into the atrium during the systolic phase of the cardiac cycle , when the ventricular muscle contracts to force blood out into the pulmonary artery.

If the valve becomes damaged - such as occurs with chronic valvular degeneration (or endocardiosis) the blood leaks back (called regurgitation) into the atrium and causes an abnormal heart sound (murmur) which can be heard loudest over the 4^th intercostal space on the right hand side of the chest wall. On X-rays the affected atrium and ventricle may appear enlarged.

Last updated : October 2013