Santa Anita Park will conclude its autumn racing meet Sunday, one day after a 4-year-old gelding running in the $6 million Breeders' Cup Classic became the fifth horse to die during the 23-day meet, and the 37th since December.
Mongolian Groom was euthanized following a serious fracture to his left hind limb in the stretch of the 1 1/4-mile race on dirt.
Mongolian Groom "was immediately attended to by an expert team of veterinarians, led by board-certified veterinary surgeon Dr. Ryan Carpenter," according to a statement from Breeders' Cup Ltd.
"During their evaluation at the equine hospital at Santa Anita, they observed a serious fracture to his left hind limb. Radiographs were taken and a complete evaluation was performed. Given the extent of the injury, Dr. Carpenter, in consultation with (a team of doctors) recommended humane euthanasia of Mongolian Groom," the statement said.
Mongolian Groom was the third horse to die at Santa Anita Park in nine days and 37th since December, which has sparked controversy among animal rights activists and efforts to improve horse safety.
Renowned veterinarian Dr. Larry Bramlage will conduct an independent evaluation.
As mandated by the California Horse Racing Board, Mongolian Groom will undergo a necropsy at the University of California Davis School of Veterinary Medicine.
The fatality came in the 14th and final race of the otherwise injury-free two-day $28 million Breeders' Cup World Championships, which was held for a record 10th time at Santa Anita.
Mongolian Groom won three times in 17 career starts, finished second twice and third three times, earning $579,141. He won his final start before the Breeders' Cup, the Grade 1 Awesome Again Stakes Sept. 28 at Santa Anita.
"The death of Mongolian Groom is a loss to the entire horse racing community," the Breeders' Cup statement said. "Our equine and human athletes' safety is the Breeders' Cup's top priority. We have worked closely with Santa Anita leading up to the World Championships to promote enhanced equine safety."
"Santa Anita has implemented numerous industry-leading reforms to enhance the existing health and safety measures with the intent of providing a safe racing environment."
"In addition, Breeders' Cup always observes the most thorough up-to-date medication practices and restrictions, testing protocols, equine security and surveillance program, veterinary exams, injury management protocols and racing surface testing."
The statement said the measures were in place to "ensure our athletes are racing under the safest and most transparent conditions possible."
Breeders' Cup Chief Executive and President Craig Fravel said Wednesday that "everything humanly possible" was done to try to prevent horses from being injured during the event.
Sen. Dianne Feinstein, D-California, sent a letter to Rick Baedeker, executive director of the California Horse Racing Board, on Wednesday, writing that the Breeders' Cup "presents a critical test for the future of horse racing in California and in the United States."
"If horse racing cannot be conducted in a safe and humane manner that protects the life and safety of horses and jockeys, it may be time to reexamine the future of this sport in our state and in our country," Feinstein wrote.