Amy Polkes, DVM, Dipl. ACVIM, performs a cardiac exam. | Photo: Courtesy Dr. Amy Polkes

No one wants to hear their horse has a heart murmur. The diagnosis can raise many questions: Is my horse safe to ride? Is my horse going to die? Is there anything I can do? The answers to those questions usually require a deeper dive into the diagnosis to determine the specific type of heart murmur the horse has and how significant it might be.

Amy Polkes, DVM, Dipl. ACVIM, provides cardiac evaluations through her mobile practice, HV Equine Internal Medicine, which serves Maryland and the surrounding states. She discussed heart murmurs during a recent presentation at the 2020 Northeastern Association of Equine Practitioners Symposium.

Characterizing the Murmur

Most people are familiar with the two-beat “lub-dub” sound a normally functioning heart makes. The beats correspond to valves closing as blood flows through the heart. The first heart sound (lub) happens when the mitral and tricuspid valves close and is referred to as S1. The second heart sound (dub) takes place when the aortic and pulmonic valves close and is referred to as S2