Work

Spontaneous Reduction in Mitral Valve Regurgitation in Three Dogs With Severe Myxomatous Mitral Valve Disease: An Unusual Case Report

Year: 2026

Type: article

Abstract: BACKGROUND: Myxomatous mitral valve disease (MMVD), the most common heart disease in small-breed dogs, is characterized by mitral regurgitation (MR) resulting from valvular degeneration, which may progress to left-sided heart failure. This report describes the cases of three dogs with severe MMVD (American College of Veterinary Internal Medicine Stages C or D) who exhibited an unexpected spontaneous reduction in MR despite continued valve degeneration. CASE PRESENTATION: Three dogs initially presented with symptoms of heart failure and left atrial and ventricular enlargement. Standard treatment, including diuretics, improved their conditions; however, further monitoring revealed that the coaptation gap decreased due to mitral valve thickening, leading to a reduction in MR. This was accompanied by a significant decrease in heart size. As a result, diuretics were discontinued, and all dogs were successfully managed with pimobendan alone. CONCLUSIONS: To our knowledge, this is the first report of spontaneous MR reduction in MMVD, where coaptation gap narrowing played a role in clinical improvement. These cases may broaden the current understanding of MMVD progression, suggesting that, in rare instances, changes in cardiac remodelling and clinical status can occur. Further research is warranted to better understand the underlying mechanisms.

Source: Veterinary Medicine and Science

DOI: 10.1002/vms3.71155

Authors: Hyo‐Seung Nam, Yein Oh

Institutions: Kyungpook National University, Busan Medical Center, The Schwarzman Animal Medical Center

Language: English

Topic: Cardiac Valve Diseases and Treatments

Subfield: Cardiology and Cardiovascular Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,880