LOUISVILLE, Ky. — The deaths of racehorses during Kentucky Derby Week and the Spring Meet in 2023 shook the horse racing world.
12 horses died at Churchill Downs over two months, a number considered "unusually high" to a national horse racing safety entity.
In the months that followed, the Horse Racing Integrity and Safety Authority (HISA) formed a work group to investigate exercise-associated sudden deaths—deaths of clinically healthy horses during or within an hour of exercise.
Dr. Karen Hassan, HISA’s compliance and research veterinarian, told WHAS 11 that the organization conducted a retrospective analysis of horses that died from exercise-associated sudden death (ESAD).
"During that analysis, we found the largest number to be horses early in their career, between zero and five s