Several horses from trainer Mark Casse’s barn at Woodbine racetrack were found ailing Oct. 2, which led to some speculation that the animals had been tranquilized. The Ontario Racing Commission has promised an investigation into an incident in which eight of Casse’s horses, all owned by Harry T. Mangurian Jr., were found suffering from excessive diarrhea and had their eyes “half shut.”

The horses, all of whom are expected to recover, included several that had been scheduled to compete that day, the following afternoon, and in races in the upcoming week, Casse said. One of them, the 2-year-old colt Valid N Bold, could be one of the favorites for the Oct. 12 Grey Stakes, and if he runs well, could compete in the Breeders’ Cup Juvenile (gr. I) Nov. 7.

Casse, one of the leading trainers at Woodbine, has reason to believe that someone may have tampered with the horses. Some of the male horses could not hold their genitals up for two days, and all of the animals appeared depressed.

Casse said he initially thought the horses could have been suffering from colitis–an inflammation of the lining of the colon–but noted that most of them would have died. Initial blood tests ruled out any type of virus, and further blood and urine tests were to be done