ARCADIA (CBSLA) – A horse had to be euthanized Wednesday after suffering a shoulder injury during a workout at Santa Anita Park in Arcadia.

River Derby, a 2-year-old colt, is the 27th horse to die while racing or training at Santa Anita since Dec. 26.

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FILE — The main track sits empty at Santa Anita Park on March 10, 2019, in Arcadia, Calif., after horse racing was temporarily suspended following a slew of horse deaths. (Getty Images)

River Derby suffered a fractured shoulder during a routine gallop Wednesday morning, according to park spokesperson Mike Willman. The colt was taken to Chino Valley Equine Hospital, where he was diagnosed and later euthanized.

River Derby had taken part in three workouts at Santa Anita, but had not yet raced, Willman said. He had been purchased in March for $50,000 in Florida.

The horse’s trainer, Ruben Gomez, told the Los Angeles Times the fractured shoulder “can be a common injury in babies.”

The last horse death at Santa Anita had been on May 26 when Kochees, a 9-year-old gelding, was put down a day after suffering a leg injury during a race. Kochees was the third horse to die at the track within nine days, following a roughly six-week span with no deaths.

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Animal rights advocates, along with California Sen. Dianne Feinstein and other politicians, have demanding racing stop until an investigation into the exact cause of deaths can be completed.

Racing at Santa Anita was temporarily suspended in February – following the 19th horse death — and again for most of March – following the 21st horse death — so experts could conduct testing on the park’s three tracks – the main, training and turf tracks — to try and pinpoint the issue. None of the horse deaths have occurred on the training track.

On March 31, just two days after racing had resumed, a 5-year-old gelding named Arms Runner had to be euthanized after being injured during a race when he fell following a collision with another horse while both were transitioning from the turf course to dirt.

In mid-March, Santa Anita officials announced a series of new measures to help bolster the safety of horses at the track, including restrictions on certain medications, requiring trainers to get permission in advance before putting a horse through a workout and investing in diagnostic equipment to aid in the early detection of pre-existing conditions.

Also in April, Los Angeles County District Attorney Jackie Lacey announced the creation of a task force to investigate the deaths.

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(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. City News Service contributed to this report.)