Unlike human athletes, racehorses are allowed a myriad of performance-enhancing drugs. But in recent years, the practice has been put under a microscope.
"I think the sport of racing is at a crossroads," said ESPN reporter Jeannine Edwards, who covers horseracing. "They know that the sport needs to be cleaned up."
This year, the Kentucky Derby banned anabolic steroids, but many other drugs remain available to trainers.
Last summer on Capitol Hill, Hall of Fame trainer Jack Van Berg described the sport's drug use in stark terms.
"It's like chemical warfare," Van Berg told a Congressional subcommittee. "It's gotten, as far as I'm concerned, plumb out of hand."
Horse breeder Arthur Hancock agrees. He says he once asked a veterinarian not to administer unnecessary drugs to his horses.
"He said, 'Arthur, you want to win races, don't you?'" Hancock said.
Critics say anti-inflammatory medications are often misused to eliminate pain and allow an injured horse to keep running.
"The potential danger is that you've got a problem that it's masking, and that becomes a major issue during the race," said Wayne McIlwraith, a veterinarian at the University of Colorado who specializes in joint injuries in horses.
But many in this sport of kings say fatal injuries are inevitable, drugs or no drugs. This week alone, two horses at Churchill Downs have been euthanized following catastrophic injuries in pre-Derby races.
"Any time you have a 1200-pound animal racing around on little ankles that are as big as my wrist, literally, accidents can happen," Edwards said.
In fact, at last year's Derby, runner-up Eight Belles was drug-free and healthy when she shattered two legs and had to be euthanized.
Eight Belles' owner, Rick Porter, returned to the Derby this year with another drug-free horse, Friesan Fire, and says banning all drugs is the only way to rehab racing's dubious image.
"I don't think our fans have any faith in our [current] system," he said.