Diodoro Suspended, Fined for TCO2 Violation at Oaklawn

Robertino Diodoro, the leading trainer at Oaklawn Park during its 2022-23 season, received a 30-day suspension and $1,000 fine from the Arkansas Racing Commission May 15 for a horse that raced with an excessive level of total carbon dioxide in its blood.

Total carbon dioxide level, known more succinctly as TCO2, 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.

The violation occurred with a 3-year-old colt named Aristocracy , who made his first start for Diodoro and owner Gordon Christoff April 22 in the Bath House Row Stakes at Oaklawn, where he finished sixth. The colt previously raced three times for owner/breeders Gary and Mary West and trainer Brad Cox.

After the Bath House Row Stakes, Industrial Laboratories found Aristocracy had a TCO2 content of 42.3 mmol/L. Arkansas Racing Commission regulations state TCO2 levels cannot be higher than 37 mmol/L.

Diodoro waived his rights to a stewards' hearing and waived his right to an appeal, but he insisted to BloodHorse the horse had not been "milkshaked." The trainer did say his horses get baking soda added to their feed to help manage against ulcers and prevent tying up, which is severe muscle spasms that can follow strenuous exercise.

"We have been supplementing with baking soda for years. It is a natural substance you buy at the grocery store and we've never had a problem," Diodoro said. "Are we milkshaking? Of course not. This is 2023 and 99% of the racetracks are testing for it, so why would you do it?"

Diodoro said he has no clear answers about what caused the excessive TCO2 level, but a couple of veterinarians have suggested to him a couple of possibilities. First, the horse was training the morning of the Bath House Row Stakes, and Diodoro was told that can increase blood carbon dioxide levels. Second, the colt raced on Lasix, a medication given to prevent exercise-induced pulmonary hemorrhage. Several studies have shown a correlation between the use of Lasix, which is furosemide, and elevated TCO2 levels.

A study called Equine Total Carbon Dioxide Testing in Illinois in 2012, which was published in the Journal of Analytical Toxicology in October 2014, found the administration of furosemide has an effect on the mean concentration of TCO2, raising it from 29.3 to 31.1 mmol/L throughout a calendar year.

"TCO2 concentration is dependent on several factors. The probability of exceeding regulatory thresholds is affected by such things as seasonal variations and furosemide administration," the study stated within its conclusion. "Regulatory officials should take into account such variations as Lasix administration, gender and track temperature in assessing penalties."

Aristocracy has raced four times, twice with Lasix. He was not given Lasix in the last race he ran for the Wests, in the March 4 John Battaglia Memorial Stakes at Turfway Park.

Diodoro has not had a medication positive since May 2020, according to trainer ruling histories available through the OwnerView website.

"I can't tell you why this one turned up positive," Diodoro said. "I don't want to make a big stink and get lawyers and drag this out; I don't want to do all that. I think we see too much of that, so I'm just going to take it like a big boy and hope it doesn't happen again."

Diodoro actually will serve 15 days from Dec. 8-22, 2023, which corresponds with the opening days of the next Oaklawn meet. The remaining 15 days are stayed on the condition that no Class A or Class B medication violations occur in any racing jurisdiction within 365 days from May 15, according to the ARC ruling.