How to Diagnose Aortic and Mitral Regurgitation in Older Horses: A Case-Based Approach

The identification and interpretation of equine murmurs can be improved. In older horses, the two common degenerative valvular conditions are mitral and aortic regurgitation, which occur with approximate equal frequency. Mitral regurgitation produces a systolic murmur. These are often blowing in character. If the murmur occupies all of systole the pulse wave in a peripheral artery can be palpated at the same time the murmur is ausculted. Aortic regurgitation results in a diastolic murmur; loud aortic regurgitant murmurs usually occupy all of diastole, many contain harmonics and are musical in character. In these cases the peripheral pulse wave is palpated in the murmur free interval. Author’s address: Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, 52 Campus Drive, Saskatoon, Saskatchewan S7N 5B4, Canada. © 2002 AAEP.