British horse racing has started using heart monitors on a select group of thoroughbred racehorses to gain better understanding of exercise-related sudden death (EASD), according to a report by the Telegraph. The article notes that EASD affects about 0.04 percent of British racehorses, with roughly half of these cases thought to be linked to heart issues. However, pinpointing the exact cause of death is challenging, as autopsies often fail to provide definitive answers.
Dr. Sally Taylor, Head of Equine Regulation, Safety and Welfare at the British Horseracing Authority, explained that monitoring the electrical activity of horses’ hearts during races and training could reveal why some horses suffer cardiac arrests. The ultimate aim is to develop screening measures to prevent such incidents.
Dr. Ceila Marr, editor of the Equine Veterinary Journal, highlighted that heart monitors for horses have only recently become available for use in both training and racing. She compared current technology to a large Apple Watch capable of collecting ECG data easily and in volume, though she noted this is still less precise compared to the advanced EKGs performed at the Newmarket Equine Hospital.
Two types of devices have been trialed: at the start of summer, 10 horses wore Arioneo Equimetre devices around their girths during races, and another 10 will soon compete with Equimetrics saddle pad heart monitors. Collecting each ECG reading takes around 30 minutes. Marr observed that a horse’s heart rate rises by about 10% during races compared to relaxed conditions, and the heart rhythm becomes much more variable.
To handle the large data sets generated, Marr is collaborating with the University of Surrey to develop an AI program that will help analyze the ECG information and support expansion of the monitoring program in the future.
This article was originally published by Paulick Report on December 2, 2025, within their Horse Care section.
Fan Take: This advancement in equine heart monitoring is a significant leap forward for horse racing safety. By gaining deeper insights into cardiac risks, the sport can better protect its equine athletes, ensuring healthier competition and potentially saving lives.

