Multiple graded stakes-winning trainer Robertino Diodoro, currently second in the Oaklawn Park trainer standings, has been cited for possession of the banned substance levothyroxine and faces up to a two-year suspension. The case has not yet been fully adjudicated.
The infraction against the trainer was first posted on the Horseracing Integrity and Welfare Unit website March 29, although the findings date back to March 13. Levothyroxine, a thyroid supplement and synthetic version of a hormone called thyroxine, is banned by HIWU after years of overuse in the racing industry. Thyroid hormones serve to promote oxygen consumption, regulate the synthesis of various proteins, control body heat production, and stimulate metabolism.
Diodoro has been summarily suspended until the case has been reviewed by HIWU's Internal Adjunction Panel and then by a federal administrative law judge. He has hired Arkansas-based attorney John Holleman for representation.
Asked to comment, Diodoro directed BloodHorse to Holleman, who did not respond.
Oaklawn Park president Louis Cella told BloodHorse that the substance was uncovered during a routine inspection of Diodoro's barn at the Hot Springs, Ark., track.
"Oaklawn views the integrity of our sport as the highest priority and working with HIWU and (the Horseracing Integrity and Safety Authority) we now have the tools to facilitate a very quick and appropriate outcome (for infractions)," Cella said. "HISA can now run tests and assist in the investigation so that it's expedited as opposed to our traditional industry standard, which would've taken very long."
Upon discovering the levothyroxine, Diodoro was told to leave the Oaklawn premises immediately and that all of the trainer's horses stabled at the track would need to be removed from the property as of March 31, Cella said. Under HISA rules, Diodoro is allowed to race his horses that were previously entered at Oaklawn Friday and March 30 but is prohibited from entering further horses in any race, Cella added.
The trainer had three starters Friday, winning the fifth race with Mystery Mo and later the $200,000 Temperence Hill Stakes with Masqueparade, and finishing second in the 10th with Promisemeanempire. He has Mockingbird Stakes winner Midshipman's Dance, co-owned by Holleman, entered in Saturday's $750,000 Fantasy Stakes (G2).
He also has horses entered to race in early April at Turf Paradise in Arizona.
Last May, Diodoro was given a 30-day suspension and a $1,000 fine from the Arkansas Racing Commission for a horse that raced with an excessive level of total carbon dioxide in its blood. He served 15 days over the start of the Oaklawn meet, Dec. 8-22, with 15 days stayed on the condition that no Class A or Class B medication violations occur in any racing jurisdiction within 365 days from May 15, 2023, according to the ruling. The Association of Racing Commissioners International classifies levothyroxine as penalty Class C.
Carbon dioxide is monitored by regulators to identify cases of "milkshaking," a practice of dosing a horse with a sodium bicarbonate solution in order to attempt to reduce the fatigue caused by lactic acid buildup in muscles during a race.
Diodoro waived his right to a stewards' hearing and his right to an appeal, but he insisted in a spring 2023 interview with BloodHorse that the horse testing positive, Aristocracy, had not been "milkshaked." The trainer did say his horses get baking soda added to their feed to help manage ulcers and prevent tying up, which is severe muscle spasms that can follow strenuous exercise.
After Diodoro completed the suspension, Oaklawn allotted the trainer stalls for 2023-24.
"Because of our stewards, the punishment we gave Diodoro was a 30-day suspension, which he did do," Cella said. "We gave him stalls this year under the understanding that he was aware he would not get another strike. He has a full barn, he has a lot of horses, and several different owners, and we thought it was only fair to give him another chance, so to speak. And we tell that to everyone. At Oaklawn, we are going to understand and listen to you and see if there is a reason to give someone a second chance, but that's it.
"There was no surprise with this," Cella said.
In recent cases adjudicated and posted on the HIWU website, trainers found in violation for levothyroxine have been issued lengthy suspensions, ranging from 14 months to two years. The most serious of these penalties was given to trainer Natalia Lynch, who was issued a two-year suspension and $25,000 fine last July when found in possession of levothyroxine in the form of Thyro-L.
Note: For clarity that the finding is an allegation, the headline of this story has been updated.
