Oatman, the winner of the $215,600 Los Alamitos Winter Derby for Quarter Horses in February, was euthanized at an equine hospital in Las Vegas on Thursday, according to Holly Skeen, the wife of trainer Mark Skeen.
Holly Skeen did not divulge the cause of Oatman's death, but said that veterinarians attempted to save the 3-year-old.
"They did everything they could," she said.