In general, dogs diagnosed with congestive heart failure can live from 6 months to 1.5 or 2 years. Pimobendan is a phosphodiesterase (PDE) III inhibitor with positive inotropic activity (by increasing the sensitivity of the contractile apparatus to calcium) and vasorelaxant effects (by inhibiting phosphodiesterase) Pimobendan may be used to provide short-term relief of cardiac function in dogs with congestive heart failure (CHF) due to muco-mucovascular mitral valve disease (MMVD). In addition, Pimobendan, in combination with conventional therapy, may prolong the time to sudden death, euthanasia from cardiac causes, or treatment failure in dogs with CHF due to MMVD. By using Pimobendan, dogs with enlarged hearts but without heart failure gained an additional 60% or 462 days of life.