Chronic Valve Disease in Dogs

Myxomatous Mitral Valve Degeneration (i.e. Chronic Valve Disease or Endocardiosis) is a chronic, degenerative disease of the mitral valve (62% of affected patients have only mitral valve changes).

The normally thin and delicate valve leaflets are damaged and the tissue replaced with a thickened, non-pliable tissue.  

This causes the valve leaflets to become thickened, irregular, and have poor coaptation (closure).  

This poor coaptation allows reverse blood flow (left ventricle into left atrium), which is termed regurgitation or insufficiency.  

This disease is progressive and unfortunately, there is no cure.  

Routine rechecks are required to monitor for any changes to the left atrium or ventricle that may warrant additional testing or direct medical management of this disease.  

Eventually, this disease can lead to the development of congestive heart failure (fluid in the lungs), which is a medical emergency that makes breathing very difficult.  

This disease can also affect the tricuspid valve (right side of the heart) and cause similar problems.  

One study indicates 32.5% of cases have concurrent mitral and tricuspid valve degeneration.  This study indicated 1.3% of affected patients have only tricuspid valve changes.