People for the Ethical Treatment of Animals is seeking the suspension of Eight Belles' jockey after the filly had to be euthanized following her second-place finish in the Kentucky Derby on Saturday.
Gabriel Saez was riding Eight Belles when she broke both front ankles while galloping out a quarter of a mile past the wire. She was euthanized on the track.
PETA faxed a letter Sunday to Kentucky's racing authority claiming the filly was "doubtlessly injured before the finish" and asked that Saez be suspended while Eight Belles' death is investigated.
"What we really want to know, did he feel anything along the way?" PETA spokeswoman Kathy Guillermo said. "If he didn't then we can probably blame the fact that they're allowed to whip the horses mercilessly."
Eight Belles trainer Larry Jones said the filly was clearly happy when she crossed the finish line.
"I don't know how in the heck they can even come close to saying that," Jones told The Associated Press on Sunday. "She has her ears up, clearly galloping out."
Guillermo said if Saez is found at fault, the group wants the second-place prize of $400,000 won by Eight Belles to be revoked.
Saez, a 20-year-old Panama native, was riding in his first Kentucky Derby. He frequently rides for Jones.
A call to the jockeys' room at Delaware Park, where Saez raced on Sunday, went unanswered.
Eight Belles, the first filly since 1999 to run in the Derby, appeared fine until collapsing while galloping out after the finish.
The letter to the Kentucky Horse Racing Authority also sought a ban on whipping, limits on races and the age of racehorses, and a move to softer, artificial surfaces for all courses.