A second blood test of the horse came back positive for the presence of the banned steroid betamethasone, which could result in disqualification and discipline for Hall of Fame trainer Bob Baffert.
Medina Spirit, the 2021 Kentucky Derby winner, collapsed and died after a workout at Santa Anita Park on Monday morning.
The California Horse Racing Board's Equine Medical Director Jeff Blea confirmed the 3-year-old horse's passing and said that he ordered a comprehensive autopsy be done to determine the cause of death.
According to reports, jockey Juan Ochoa was riding Medina Spirit when the horse collapsed.
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Trainer Bob Baffert had not released an official statement on Medina Spirit as of Monday afternoon.
Medina Spirit, a 3-year old thoroughbred, was the son of Protonico.
Medina Spirit's win at the 2021 Kentucky Derby is still up for dispute after the horse tested positive post-race for betamethasone -- a medication that is banned on race day.
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No ruling has been made by the Kentucky Horse Racing Commission on whether or not Medina Spirit's Kentucky Derby win will be disqualified.
Medina Spirit is hardly the first horse to die at Santa Anita.
Fight On Ron, a 2-year-old gelding, suffered a racing injury at Santa Anita Park and was euthanized in October 2021.
That death came two days after a 2-year-old unraced filly named Seven Summers was injured during training and euthanized at Santa Anita.
Natural History, a 4-year-old gelding who had 13 starts and two victories, suffered a fractured left front ankle in February and was euthanized after a workout at Santa Anita Park.
Ebeko, a 2-year-old colt, sustained an injury to his left front leg and was euthanized at Santa Anita one day after the racing season started in December 2020.
