At least two horses have died and others have fallen ill from what officials fear may be a mysterious sickness spreading in the boarding stables at the Orange County Fairgrounds Equestrian Center.
The unexplained sickness forced a quarantine Friday of the 250 privately owned horses boarded at the large equestrian center, Orange County Fairgrounds spokeswoman Jill Lloyd said.
"We have no idea what has been happening," Lloyd said, adding that veterinarians and other experts are baffled by the illnesses. "It is very strange, and very sad," she said.
Pamela Gimple, equestrian center manager, said that three horses suddenly became ill after the morning feeding.
"We don't know why that happened," Gimple said. "Right now we don't have any answers."
One horse had to be destroyed, she said. It was taken to a state pathology laboratory in San Bernardino, where an autopsy was said to be in progress Friday night. One ailing horse was transferred to a stable in Chino, and another remained in Costa Mesa, stable officials said.
Gimple said that Dr. John Byrd, an Irvine veterinarian who requested the quarantine, was called to the center to take blood tests.
"They are running tests on the food, the bedding and the water," she said, adding that the cause of the illness may not be known for at least 24 hours. "These things take time," she said.
Byrd said "it's too early to tell" what happened. He declined to speculate, saying only that he has consulted with various laboratories and universities.
According to Lloyd, stable personnel
found the first sick horse last Saturday, when a 4-year-old suddenly collapsed in its stall.
The horse appeared paralyzed and sweated profusely, although its temperature remained low, she said. Its eyes became glassy and it could not stand up, she added.
That horse suddenly died, Lloyd said. The owners, however, did not request an autopsy.
Lloyd said workers at the equestrian center considered the incident an anomaly until Friday morning, when they discovered four more horses exhibiting similar symptoms. Two died Friday, she said.
"They all just went down," Lloyd said. "They laid down and couldn't get up."
Lloyd said she thought that Byrd had ruled out the possibility of food poisoning; Byrd and Gimple declined to say whether food poisoning was no longer suspected. They also said that only three horses fell ill Friday.
While Lloyd said that three horses had died of similar symptoms since last Saturday, Byrd said two horses had died.