Trainer Mike Mitchell was taken to Centinela Hospital Medical Center by ambulance June 16 after collapsing on the track at Betfair Hollywood Park following the sixth race.
The Hollywood Park publicity office confirmed the 65-year-old trainer was transferred to Centinela but had no information on his condition. Mitchell's horse, Gutshot Straight, won the $40,000 claiming race by a neck over favored Chapman's Peak.
TVG reported that Mitchell suffered a seizure after leaving the winner's circle and was treated at the scene before being transported to the hospital.
Mitchell underwent surgery June 29, 2012, to remove a brain tumor.
A trainer since 1974, Mitchell has 2,655 career winners from 12,333 starters with lifetime purse earnings of more than $65.3 million. He ranks ninth in the current Hollywood Park spring meet standings with eight winners from 37 starts.