Myxomatous mitral valve disease (MMVD) is the most common heart disease in dogs. It is the most common cause of a heart murmur in adult small- to medium-sized dogs, especially Cavalier King Charles spaniels, dachshunds, Yorkies, Chihuahuas, and mini poodles.
Myxomatous degeneration of the tricuspid valve can also occur.
Stage dogs with MMVD to determine the need for intervention – use thoracic radiographs, +/- echocardiogram, +/- ECG. Asymptomatic dogs with a heart murmur and normal thoracic radiographs are considered class B1. Do not treat class B1 dogs, but monitor for progression. Progression can be slow to negligible.
There is no Tx that slows or reverses MMVD; however, dogs with cardiomegaly (i.e., class B2) benefit from Tx with pimobendan to slow progression to congestive heart failure (CHF). If CHF is present, Tx to alleviate clinical signs and improve quality of life.
More invasive procedures, such as mitral valve annuloplasty, transcatheter edge-to-edge repair, and chordae tendineae replacement, have been undertaken in research settings and some client-owned dogs at a few facilities around the world. The use of these procedures in veterinary medicine is still in its infancy, and as such, medical management of MVD remains the standard of care at this time.
Read the useful and informative American College of Veterinary Internal Medicine consensus guidelines for the diagnosis and treatment of mitral valve disease.
