What to do with Thoroughbred racehorse Doug O’Neill and his most recent drug positive in New York that resulted in a 45-day suspension for the Southern California-based trainer and a ban from participating in the Breeders’ Cup World Championships?

O’Neill was suspended when a gelding named Wind of Bosphorus tested positive for oxazepam, a Class 2 drug considered by the Association of Racing Commissioners International to have a high potential to affect performance. Class 2 drugs include generally accepted therapeutic medications with “high potential for abuse.”

Oxazepam is in the same drug family as diazepam, or Valium, which is a muscle relaxant. According to the New York State Gaming Commission, the drug was administered within a week of the horse’s race June 2, 2013, which is a violation of state regulation.

Though O’Neill has already accepted his suspension, his problems don’t stop in New York.

O’Neill got a lot of unwanted publicity during the 2012 Triple Crown when his stable’s star I’ll Have Another had a bead on the Triple Crown title until injury sidelined him the day before the Belmont Stakes. During a high point of his career, the trainer was also cited for a total carbon dioxide violation in a filly named Argenta when she raced at Del Mar Aug. 25, 2010.

Total carbon dioxide (commonly referred to as TCO2) in the blood is what is monitored to identify cases of “milkshaking,” or tubing a horse with a bicarbonate of soda mixture that lowers the build up of lactic acid in the muscles and reduces fatigue. A horse's TCO2 levels can also be influenced b