One of the most common equine heart abnormalities is an irregular heartbeat called atrial fibrillation, or AF.

In some horses, signs of AF include poor performance, labored breathing and coughing. But sometimes AF is only noticed by the veterinarian during a routine checkup.

AF can be treated with medication, but side effects are common. The University of Florida’s Large Animal Hospital is the only equine veterinary clinic in Florida using a treatment called electrocardioversion. Electrical leads threaded through a vein and into a horse’s heart deliver a controlled shock to convert AF to a regular heartbeat. In nearly 100 percent of these horses, treatment is successful and there are no post-procedure complications.

The earlier AF is diagnosed and treated, the better the outcome. So it pays to listen to the rhythm.