Trainer Claude R. “Shug” McGaughey has been suspended 15 days by the Ohio State Racing Commission for a positive for a prohibited diuretic, hydrochlorothiazide, detected in a post-race test of a horse that won at Belterra Park in Ohio last September. Tactical Affair,  a now 5-year-old Tapit mare owned by the Phipps Stable, tested positive for the substance after winning a non-winners of two allowance at Belterra on Sept. 9 last year, 17 days after she won a maiden race at the same track. The suspension began on Feb. 6 and runs through Feb. 20, according to a ruling from the commission. McGaughey was also fined $500, and Tactical Affair was disqualified from the race. Hydrochlorothiazide is a Class 4A substance, considered to have little to no performance-enhancing effects on a horse, but racing rules prohibit the substance from appearing in post-race tests. William Crawford, the executive director of the Ohio State Racing Commission, said that McGaughey was “totally cooperative” with stewards and racing officials during an investigation into the positive. McGaughey dropped an appeal of the penalty on Feb. 4 after a split sample confirmed the presence of the substance. “He just wanted to go through the process, make sure everything was proper,” Crawford said. McGaughey said on Monday that he does not use the substance on any of his horses, but that the split sample and a DNA test confirmed both that the substance was in Tactical Affair’s sample and that the sample came from the mare. “It seems pretty excessive, but that’s the rule and I’m going to live with it,” McGaughey said. “Somewhere along the line there must have been a stable mistake.” He added that vet bills from the mare did not show any administrations of a substance that would include hydrochlorothiazide. McGaughey’s horses are currently starting under the name of his assistant trainer Robert Medina. The horses are based in Florida for the winter season. Under a system known as reciprocity, McGaughey is barred from entering horses in all racing states due to the Ohio suspension. According to Dr. Mary Scollay, the executive director of the Racing Medication and Testing Consortium, hydrochlorothiazide is an ingredient in a compounded substance available on backstretches to treat “lower-level leg edema, or minor inflammation.” The compounded substance was once available commercially under the trade name Naquasone. The post-race sample from Tactical Affair also included chloraminophenamide, according to the ruling. That substance was also an ingredient in Naquasone. Tactical Affair was treated with furosemide, the anti-bleeding medication commonly known as Lasix, for the Sept. 9 race, and in the other four races of her career. According to veterinary officials, it would be highly unlikely for a trainer to administer hydrochlorothiazide as an adjunct anti-bleeding medication considering the legality of raceday Lasix. McGaughey has a nearly spotless record as a trainer, and has been outspoken in his support for tighter medication rules.