The California Horse Racing Board issued a complaint against trainer William Morey on Tuesday, alleging that his assistant trainer gave two horses a substance containing an alkalinizing agent on March 29. The practice is often referred to as milkshaking and is believed to give a horse a performance boost.
Those horses were scheduled to run that day but were scratched.
Morey has not been able to enter any of his horses at either Santa Anita or Golden Gate Fields since the incident was discovered more than two weeks ago.
Santa Anita recently instituted medical and drug protocols in order to boost public confidence in the sport after the death of 23 horses at the track since Dec. 26.
Belinda Stronach, president and chief executive of The Stronach Group, announced sweeping medication reforms a couple of weeks ago. It was her desire to eventually eliminate race-day medication. The changes did not affect milkshaking, which has been illegal for a long time.