DEL MAR, Calif. -- A 3-year-old filly has collapsed and died after a workout at Del Mar, while another horse that was injured in a race on Nov. 10 has been euthanized, making it four horses that have died since the track's fall meet began Nov. 8.
Slewgoodtobetrue died in the barn area Sunday. A track spokesman says officials are awaiting the results of a mandated necropsy to determine the cause of death.
Trained by Peter Eurton, Slewgoodtobetrue had two wins in six career starts. Her last race was in April when she finished fourth in the Santa Anita Oaks.
Princess Dorian was euthanized Monday after developing laminitis in both of her hind legs, a track spokesman said.
Laminitis is inflammation of the soft tissue of the hoof. It can cause extreme pain and lead to instability in the hoof.
Barbaro, the 2006 Kentucky Derby winner, shattered his leg two weeks later in the Preakness and eventually developed laminitis and died.
Princess Dorian, a 5-year-old mare, originally sustained fractures to her left front leg in a race on Nov. 10. She underwent surgery that was deemed successful the following day and her owners and trainer Andrew Lerner were optimistic about her recovery. But laminitis quickly set in.
After Princess Dorian's breakdown, Ghost Street sustained a front leg injury in a turf race and Prayer Warrior had fractures to a front leg in a dirt race the same day. Both of those horses were euthanized.
Before the current meet, Del Mar hadn't had a horse die in racing since the 2018 fall meet.