Diodoro Provisionally Suspended By HIWU For Possession Of Banned Substance

Diodoro had four entries on Friday's Oaklawn program, including Masqueparade in the $200,000 Temperence Hill Stakes. On Saturday's Arkansas Derby card, Diodoro has Midshipman's Dance entered in the $750,000 Fantasy Stakes, an official points race for the Kentucky Oaks. Diodoro also has horses entered April 1, 2, and 3 at Turf Paradise in Arizona, where he's won multiple training titles.

When reached by telephone Friday, Diodoro declined to comment, referring a reporter to his attorney, John Holleman. Masqueparade is owned by Holleman and Midshipman's Dance is owned by Holleman in partnership with Randy Howg.

A call to Diodoro's attorney went unreturned.

Diodoro, whose 3,184 career wins ranks him 34th all time, began the 2023-'24 Oaklawn meet on suspension, from Dec. 8-22, for a TCO2 overage in a horse that ran April 22, 2023. That sanction was adjudicated by Oaklawn stewards as it occurred prior to the start of the Horseracing Integrity and Safety Authority's Anti-Doping and Medication Control Program. HIWU is the testing and enforcement arm of HISA. 

Levothyroxine is approved by the FDA for use in horses to treat hypothyroidism, a relatively rare equine condition. In August 2020, both the American Association of Equine Practitioners and Racing Medication and Testing Consortium issued warnings that the drug should not be used as a "wellness" supplement and should only be administered under the direction of a licensed veterinarian and based on a specific diagnosis. There had been reports of widespread use of the drug in some racing stables.