Amlodipine decreases mitral regurgitation volume in dogs over 7 days: A study of 24 dogs with myxomatous mitral valve degeneration

BACKGROUND: Amlodipine, a dihydropyridine calcium‐channel blocker, is currently being investigated as a treatment for myxomatous mitral valvular degeneration (MMVD). However, the effects of amlodipine on moderate or severe spontaneous MMVD, based on changes in echocardiographic indices, remain unclear. ANIMALS: Client‐owned small‐breed dogs (n = 24) with naturally occurring MMVD of the American College of Veterinary Internal Medicine (ACVIM) stage B2 or higher. METHODS: Basic dog information including previous medication treatments were recorded. All subjects received amlodipine 0.1 mg/kg, administered per os, twice daily for 7 days, in addition to their existing medication. We measured systolic blood pressure, obtained x‐ray, echocardiography, blood test data before and after 1 week of amlodipine administration. RESULTS: Left ventricular end‐diastolic internal diameter, left atrial diameter and E wave reduced statistically after 1 week of amlodipine treatment (all p < 0.001). No adverse effects were reported. CONCLUSIONS: These findings suggest that low‐dose amlodipine should be considered as treatment for dogs with ACVIM stage B2‒C MMVD.