Bob Baffert was suspended from the Kentucky Derby primarily because his horse, Medina Spirit, tested positive for a banned substance called betamethasone after winning the 2021 Kentucky Derby. Betamethasone is a corticosteroid permitted for therapeutic use but prohibited on race day according to Kentucky's equine drug regulations. Following the positive drug test, Medina Spirit was disqualified, and Baffert was handed a two-year suspension by Churchill Downs. After legal appeals and further scrutiny, the suspension was extended to three years, lasting through the 2024 Kentucky Derby cycle. Baffert initially claimed the presence of betamethasone was from a topical ointment used for a skin condition on Medina Spirit and took responsibility for the substance found in the horse. Churchill Downs eventually lifted the suspension in July 2024 after Baffert accepted accountability for the incident, allowing him to return to compete in the Kentucky Derby in 2025.