Grayson-Jockey Club Research Foundation Tackles Sudden Deaths in Horses

Jamie Haydon, president of Grayson, stated, "In eventing, we ask our horses to be brave, powerful, and endlessly giving—especially across cross-country, where the physical demands are greatest. When even the healthiest horse can carry hidden cardiac risk, research becomes our most important safeguard. It gives riders the knowledge to make better decisions through early detection, the confidence to compete responsibly, and the ability to protect the partner who gives them everything.”

Cardiac conditions are estimated to account for about half of exercise-related sudden deaths in horses. Many animals have underlying heart rhythm irregularities that are not easily detectable, and significant cases remain unexplained even after post-mortem evaluations.

“Despite advances in veterinary medicine, critical unknowns persist,” Haydon said. “Our goal is to move the industry from reacting to these events to preventing them altogether.”

The Grayson-funded research is making progress in several areas:

- Advancing cardiac monitoring tools for earlier risk detection

- Supporting large-scale studies to identify patterns and underlying causes

- Fostering collaboration among veterinarians, researchers, and industry leaders

- Promoting proactive, data-driven prevention strategies

Recent studies have provided meaningful insights into equine cardiac health. Dr. Annelies Decloedt at Ghent University is researching Ketodoxapram, a new pharmacological approach targeting specific cardiac channels to treat atrial fibrillation safely and effectively.

At the University of Minnesota, Dr. Molly McCue and Dr. Sian Durward-Akhurst are developing innovative methods to predict exercise-associated arrhythmias using resting electrocardiograms (ECGs). Preliminary results suggest that just one minute of resting ECG data could identify horses at higher risk, providing a scalable screening tool.

Researchers have also gathered over 5,400 ECGs from more than 1,100 Thoroughbred racehorses in one of the most comprehensive studies to date. Initial findings indicate that while arrhythmias are common—sometimes even in healthy horses—distinguishing between benign and serious irregularities remains a challenge. The goal of this study is to improve ECG interpretation and develop predictive tools based on heart rate variability, offering clearer guidance for veterinarians and regulators regarding necessary interventions.

These advancements are set to benefit the broader equine industry by aiding veterinarians in their diagnoses, assisting trainers in decision-making, and helping regulators protect horse welfare, ultimately ensuring the safety of both equine and human athletes.

With traditional funding for equine research diminishing, ongoing philanthropic support is crucial for continued progress. Haydon emphasized, “Every breakthrough begins with investment in science. Through continued support, we can turn unanswered questions into life-saving solutions.”

For more information about the Grayson-Jockey Club Research Foundation, visit grayson-jockeyclub.org.