Story highlights A PETA sting targets one of America's top horse trainers

Covert recordings capture grueling images, apparently incriminating conversations

The animal rights group is known for its purist approach to animal rights

Attorney for accused trainer says "the PETA piece is sensationalism"

The Kentucky Derby resides on a summit of high-society pomp.

But with the clink of champagne glasses, the flutter of feather-bedecked sunhats and the drumming clomp of purebred hooves just weeks away, animal rights advocates may have turned over a rock, revealing an alleged equine hell beneath it.

Injured horses compete under peak demands, PETA said. It alleges they are doped against the excruciating pain of worn-out joints, hooves with holes and bleeding lungs.

Their handling and training are so grueling, prized chargers drop dead before making it to the racetrack, People for the Ethical Treatment of Animals said.

The group targeted one of America's top horse trainers, Steve Asmussen, and his main assistant, Scott Blasi, in a monthslong undercover operation that included video recorded clandestinely.

Though the sting singled out the two men, the group said what it found is "standard practice" in the horse racing industry, where "death and injuries are business as usual."

But an attorney representing Asmussen and Blasi said "the PETA piece is sensationalism."

Ugly video

PETA backs its allegations with a lengthy report and hidden camera video that the activists posted to YouTube on Wednesday.

The images of alleged doping are grueling. They are matched by what appears to be incriminating conversations -- laden with profanity -- with workers who appear disgusted by the suffering of the animals.

The videos are edited.

Racehorses receive so much medication that they are often called "chemical horses," PETA said.

Horses in Asmussen's care received a thyroid drug to "speed up metabolism," muscle relaxants, sedatives and the diuretic Lasix to prevent lung bleeds during overexertion, the group alleges.

It did not say whether the treatments were legal or customary. But the group said one of Asmussen's primary veterinarians at New York's Saratoga Race Course said "basically all" horses trained by Asmussen are given Lasix.

PETA has a reputation for a sometimes puritanical approach to animal rights and protection, and it advocates a vegan lifestyle. The group said it has filed 10 complaints against Asmussen and others working with him in Kentucky and New York.

Authorities in those two states are taking the allegations seriously.

The Kentucky Horse Racing Commission and the New York State Gaming Commission have opened investigations based on the undercover operation.

"The behavior depicted in the undercover video and supporting materials is disturbing and disgusting," said veterinarian Scott Palmer of the Gaming Commission.

Reserving comment

Clark Brewster, the attorney representing Asmussen and Blasi, said PETA's effort "has little to do with true accusation of wrongdoing and everything to do with condemning the horse racing industry as a whole."

"PETA seems to suggest in some of the videos that somehow the horses were mistreated," Brewster said. "But if you watch the video where claims of anything improper occurred, it was in front of some of the finest equine vets in the industry. It's impossible to blame the trainers."

The attorney also said the group edited the piece "to show the most sensational parts."

PETA also accused Asmussen of paying less than minimum wage and hiring undocumented workers.

Everything that the trainer did is standard practice in the sport and done under veterinarians' guidance, said Brewster.

The recordings and allegations tarnish the shine of two of the country's top horse racetracks.

PETA said its activist obtained access to Asmussen by going to work for him, and made the recordings from April to August 2013 at the Churchill Downs racetrack in Louisville, Kentucky -- the home of the Derby -- and at New York's Saratoga Race Course.

The National Thoroughbred Racing Association -- which describes itself as a broad-based coalition of horse racing interests -- notes there aren't yet uniform rules in the sport to regulate the administering of medication, or enforcement of existing rules and laboratory testing, though there is a movement to make such blanket rules.

As to Lasix, for example, a report by a Lexington, Kentucky, lab director Richard Sams pointed out several racing commissions had once banned it only to reverse that position in the mid-1990s. The NTRA said there has been "significant progress" toward a program that has been or is set to be adopted in 14 states -- including Kentucky and New York -- approving regulated administration of Lasix by third-party veterinarians or technicians.

The New York Racing Association, which conducts racing at the Saratoga Race Course, said it was concerned about the allegations brought to the Gaming Commission.

"The New York Racing Association takes the health and well-being of its equine athletes very seriously," the group said. "We pledge to continue to work in partnership with the Gaming Commission and all industry stakeholders to promote the safety, integrity and transparency of our racing."

Churchill Downs issued a statement expressing concerns about the health of horses.

"This has always been a topic of great importance to us, and we've made long-term and far-reaching commitments to incorporate health and wellness measures for every race, every day," it said.

The racetrack describes the Kentucky Derby as "the greatest two minutes in sports."