Another racehorse dies after an injury at Santa Anita Park

Horses exercise during a morning training session at Santa Anita Park in April.

(CNN)An unraced horse named Derby River was injured in training Thursday at Santa Anita Park and became the 27th horse to be euthanized since the start of the racing season in late December at the famed California racetrack.

A spokesman for the California Horse Racing Board, Mike Marten, said veterinarians at an equine hospital in Chino determined surgery was not a viable option.
The horse was galloping during a morning training session at the track in Arcadia when it was injured, the board said.
"The board regrets the loss of any horse. We are committed to working with the entire California horse racing industry in the protection of horses and riders," officials said.
    CNN reached out to the owners, the Stronach Group, but didn't receive an immediate reply. Santa Anita Park officials also didn't respond to CNN's request for comment.
    In mid-March, the racetrack implemented stringent protocols after 22 horses died over four months, and suspended racing and training. Two days after racing resumed in late March, a 23rd horse died.
    On its website, the track owners say trainers must apply 48 hours in advance for permission to give a horse a high-speed training exercise. The track's veterinarians will assist in identifying horses that are at risk for injury, it says.
      Horses are only allowed "therapeutic medication with a qualified veterinary diagnosis from a state-licensed veterinarian," it says.
      CORRECTION: An earlier version of this story misstated the horse's name. It was Derby River.