Bob Buffett said that the horse had a heart attack after exercising.

The horse trainer announced on Monday that this year's Kentucky Derby winner Medina Spirit died of a heart attack after exercising at Santa Anita Park in California.

According to a statement from Santa Anita Park, the on-site veterinarian team caring for it determined that the 3-year-old pony fell on the track and died "suddenly" after completing a routine morning exercise.

According to Santa Anita, the veterinarian team collected blood, hair and urine samples from the horses and sent them to the California Horse Racing Commission.

According to the California agreement, a complete autopsy will be performed at the School of Veterinary Medicine at the University of California, Davis, in an attempt to determine the exact cause of this sudden death. According to the park, the results will be announced by the California Racing Commission.

After the game on May 1st, due to a positive drug test for betamethasone (a joint injection/anti-inflammatory drug), Medina Spirit's first place in the Kentucky Derby was suppressed.

The horse was found to have 21 picograms of steroids in his system, twice the legal limit. This drug is legal, but it is not valid on game days in Kentucky, Maryland, and New York, where the Triple Crown Series is held.

In June, Churchill Downs banned Hall of Fame coach Bob Buffett for two years after he was diagnosed positive.

Buffett insisted on his innocence, describing the positive test as "completely unfair" and insisting that steroids are used to treat skin rashes.

According to the Associated Press, the lawyer for trainer Bob Baffert announced on Friday that it was the topical ointment, not the injection, that caused the test to fail. The decision was made through urine samples tested in a New York laboratory.

According to the Associated Press, the Kentucky Horse Racing Commission will determine whether a test that proves that the drug is administered via an ointment rather than an injection can eliminate the positive test for Medina Spirit. According to the committee, the investigation is ongoing.

The spirit of Medina was not deprived of his victory. He also finished third in Preakness Stakes.

Buffett said in a statement: "My entire barn was destroyed by this news."

Baffert said: "The spirit of Medina is a great champion and a loved one in our family. We deeply mourn his passing." "I will always cherish the spirit of Medina. The pride and personal memory of its great spirit."

Buffett also stated that his "thoughts and prayers" are with Zedan Racing Stables, owner of Medina Spirit.

"Everyone who worked with him and took care of him will miss the spirit of Medina," Santa Anita said.

"Kentucky Horse Racing Commission (KHRC) is saddened by the death of the spirit of Medina," the commission said in a statement. "He is an important member of the thoroughbred horse racing family."

The California Racing Commission is expected to issue a statement on Monday.

Santa Anita Park made national headlines in 2019, after dozens of horses died on the racetrack in the previous season-most of them on the main track.

These deaths triggered a task force investigation by the Los Angeles County District Attorney's Office and called for closure after Governor Gavin Newsrom did not heed the California Horse Racing Commission's recommendation to suspend the race when the death toll was 29.

More than 40 horses died that season.

Although the death toll is widely known, the facility has a high safety rate and considers itself the largest training facility in the United States

According to the park, in 2019, horses competed or trained in the facility more than 420,000 times, with a safety rate of 99.99%.

Henderson Hewes, Cheryl Gendron, and Bonnie Mclean of ABC News contributed to this report.

24/7 coverage of breaking news and live events