Fairgrounds’ Mystery Illness Kills 4th Horse

A fourth horse died Saturday as officials of the Orange County Fairgrounds Equestrian Center continued to search for the cause of a mysterious sickness that has spread among horses at the boarding stables.

The lastest death occurred despite last-ditch efforts by the stable officials to save the animal’s life, said equestrian center manager Pamela Gimble.

Stable personnel transported the horse to a stable in Chino for treatment, but it died early Saturday morning.

The unexplained sickness prompted officials Friday to quarantine the 260 privately owned horses boarded at the equestrian center.

Gimble said stable personnel became suspicious early last week when a 4-year-old horse collapsed in its stall. Their suspicions grew after two more horses died Friday, she said.

The four horses that died exhibited the same symptoms, Gimble said. “They start breathing heavily, then sweat profusely, their eyes become glassy and they lose control of their muscles” as if they are paralyzed, she said.

Dr. John Byrd, an Irvine veterinarian investigating the mysterious deaths, has declined to speculate on the cause, saying that he is consulting with officials from various laboratories and universities.

On Saturday, Gimble said that a preliminary necropsy conducted on one horse proved inconclusive. “A visual examination of the horse’s vital organs failed to show anything startling,” she said. “The veterinarians (at the state pathology laboratory in San Bernardino) now plan to take samples to see whether they find anything.”

So far, the sickness appears to be confined to the Orange County Fairgrounds; other equestrian centers reported no recent deaths of horses.

Kristina Barnes, a riding instructor at Huntington Central Park Equestrian Zoo, speculated that the fairgrounds’ problem could stem from the fact that the horse feed is not kept in an enclosed shelter. “It’s very possible for insecticide or any sprays to get at it,” she said.

But Gimble said the stables’ personnel replaced the hay cubes on Friday with new stock to eliminate the possibility that the feed was contaminated. She said that at least one other horse is seriously ill from the mysterious sickness and may have to be destroyed.

“We’re all very nervous,” Gimble said. “The hardest part is not knowing what’s causing” the deaths.