Evidence-based medical therapy for mitral regurgitation in dogs

Myxomatous mitral valve disease is the most common acquired cardiac disease and a leading cause of congestive heart failure in dogs. Over the past three decades, experimental studies and clinical trials have established an expanding evidence base supporting pharmacologic interventions, particularly drugs that modulate hemodynamics or target the renin-angiotensin-aldosterone system. At the same time, gaps remain in our knowledge, and several areas of clinical practice are guided more by expert consensus or extrapolation from human cardiology than by robust veterinary data. This review summarizes current evidence for pharmacologic interventions in myxomatous mitral valve disease, including established therapies such as angiotensin-converting enzyme inhibitors, mineralocorticoid receptor antagonists, diuretics, and inodilators, as well as emerging drug classes such as angiotensin receptor-neprilysin inhibitors and sodium-glucose cotransporter-2 inhibitors. For each therapeutic class, we assess the strength of the available evidence, discuss methodological limitations of existing studies, and identify key gaps where additional research is needed to inform optimal clinical use.