Three Horse Racing Trainers Receive Lengthy Suspensions
By Kendall Jang, Staff Writer
Three Thoroughbred horse trainers have received lengthy suspensions following separate cases involving banned substances, tampering, and prohibited association, according to BloodHorse.
The Horseracing Integrity and Welfare Unit (HIWU), which enforces national anti-doping and medication rules in Thoroughbred racing, issued penalties against trainers Luis Diaz, Erin Thompson, and Dominic Duree.
Diaz received the most significant penalty: a combined 18-year suspension and $225,000 in fines. The case followed a compliance search at Turf Paradise in Arizona, where investigators reported finding injectable products containing banned substances. Diaz was also accused of tampering or attempted tampering after falsely denying ownership of a vehicle connected to the investigation.
Duree received a two-year suspension and $25,000 fine for prohibited association. Investigators found suspended trainer Carlos Sedillo in Duree’s barn at Sunland Park in New Mexico, where he reportedly had access to training records and was helping care for horses.
Ohio Trainer Suspended After Horse Tests Positive
One of the cases has a direct connection to Ohio.
Trainer Erin Thompson received the maximum two-year suspension and a $25,000 fine after her horse, Motion to Adjourn, tested positive for the banned substance clenbuterol following a June 5, 2025 race at Belterra Park near Cincinnati.
The horse received a 60-day suspension, and its results from races on June 5 and June 27 were disqualified, including forfeiture of purse earnings and awards.
Thompson contested the violation, but an arbitrator ultimately upheld the penalties.
The three cases demonstrate how national racing regulations are being used to address banned substances and other rule violations within the Thoroughbred racing industry—issues with important implications for equine health and welfare
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