Mitral Valve Disease in Dogs: Managing a Common Condition

Myxomatous mitral valve disease is the most common heart disease in dogs, and staged management from preclinical detection to heart failure optimizes welfare outcomes.

Key Facts

MVD accounts for approximately 75% of all canine heart disease
Cavalier King Charles Spaniels have a genetic predisposition and near-universal lifetime prevalence
The EPIC and DELAY trials established pimobendan benefits starting before heart failure onset
ACVIM staging system (A-D) guides treatment timing based on heart size and clinical signs
Stage B2 (enlarged heart without symptoms) benefits from pimobendan according to EPIC trial data
Diuretics, ACE inhibitors, and spironolactone are added at heart failure (Stage C)
Regular echocardiography every 6-12 months monitors disease progression and informs treatment changes

Welfare Considerations

MVD progresses slowly in most dogs, often taking years from detection to clinical heart failure. The welfare opportunity is in early detection and staged management - starting pimobendan at the right time (Stage B2) delays heart failure onset by months. Once heart failure develops, optimal medical management maintains comfort and quality of life. Home respiratory rate monitoring empowers owners to detect decompensation early. Dogs with well-managed MVD often maintain good quality of life for extended periods beyond heart failure diagnosis.

What You Can Do

Screen predisposed breeds with auscultation annually from age 2-3
Pursue echocardiography when a murmur is detected to establish baseline and ACVIM stage
Follow ACVIM staging guidelines for treatment initiation timing
Monitor resting respiratory rate daily at home as a heart failure warning sign
Maintain regular cardiology rechecks every 6 months during stable disease