Diodoro provisionally suspended by HIWU

Robertino Diodoro, a trainer who is currently second in the Oaklawn Park standings, has been provisionally suspended by the Horseracing Integrity and Wagering Unit for possession of levothyroxine, a banned substance that can stimulate thyroid function, according to a ruling posted on the HIWU website on Friday afternoon.

Diodoro declined to comment on the suspension when reached on Saturday morning.

Diodoro had a horse entered on Saturday at Oaklawn in the $750,000 Fantasy Stakes, Midshipman’s Parade, but that horse was scratched just prior to the card starting. He also has multiple horses entered on the April 1, 2, and 3 cards at Turf Paradise in Phoenix, Arizona. Those horses had not been scratched as of mid-afternoon on Saturday.

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HIWU officials said on Saturday that horses from suspended trainers are allowed to start if they were entered prior to the suspension being issued. However, HIWU also said in a statement that it had “informed Oaklawn Park track management that Oaklawn Park has it within their authority to scratch” Diodoro’s horse from the Fantasy Stakes.

Levothyroxine is an FDA approved drug to treat depressed thyroid function. It has been the target of a regulatory crackdown in racing over the past ten years after regulators discovered that the drug was being routinely administered to horses without a prescription or a diagnosis. Since HIWU took over drug-testing and enforcement in the summer of 2023, the organization has issued five suspensions for possessions of the drug, including Diodoro’s.

Possession of levothyroxine carries a recommended penalty of a two-year suspension under HIWU’s regulations.

Diodoro, who has started horses in his name since 1995 but began racking up wins in the early 2010s, has 42 wins from 182 starters this year. Lifetime, he has 3,186 wins from 15,239 starts, for a win rate of 21 percent.

Diodoro served a 15-day suspension at the beginning of the 2023-24 meet at Oaklawn after a horse he trained tested for an average of total carbon dioxide in the blood at the end of the 2022-23 meet. Diodoro denied administering any substance to the horse that would have caused the total carbon dioxide level to spike.

Regulators began enforcing limits on total carbon dioxide in the blood in the early 2000s to crackdown on a practice known as milkshaking, which is the delivery of a solution of bicarbonates and vitamins into a horse’s stomach through a nasogastric tube. The solutions increase a horse’s stamina by preventing the buildup of lactic acid in muscle tissue.

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