WELLINGTON, Florida (AP) - The sudden death of 21 polo horses at a championship event in Florida may have been caused by a toxin in the animals' feed, vitamins or supplements, veterinarians said Monday.
The horses from the Venezuelan-owned team Lechuza Caracas became ill just before a tournament match Sunday, collapsing and dying on the scene or while being treated at vet clinics or transported, officials said.
The deaths shocked this affluent equestrian and golfing community in central Palm Beach County, where the International Polo Club Palm Beach hosts the U.S. Open Polo Championship every year.
"This was devastating. It was heartbreaking, to see that many horses get sick all at once," said John Wash, president of club operations.
Dr. Scott Swerdlin, a veterinarian at Palm Beach Equine Clinic near the polo grounds, treated one of the sick horses. He said it appeared the animals died of heart failure caused by some kind of toxin that could have been in tainted food, vitamins or supplements, or by some combination of all three that caused a toxic reaction.
"A combination of something with an error in something that was given to these horses caused this toxic reaction," Swerdlin told reporters.
Toxicology tests were pending Monday.
The 60-horse team is owned by Venezuelan banker Victor Vargas but most of the horses and players are Argentine, Swerdlin said. The team travels most of the year.
Swerdlin said the 21 horses together were worth up to $2 million.
"It would take 10 years to build that string back up," he said.
The International Polo Club said in a statement that polo horses are thoroughbreds who often get used in play into their mid-teens and are frequently rotated during a match.
Swerdlin also said the Lechuza team was considered among the best of the eight teams entered in the 105th U.S. Open, which started April 3 and is slated to end with a final match Sunday.
"They were the team to bat," he said. "They have some of the greatest polo players in the world."
The Lechuza Caracas horses were being unloaded from their trailers Sunday afternoon when two collapsed and others acted dizzy and disoriented, according to the International Polo Club Palm Beach. Seven horses died at the scene and the rest while being treated elsewhere or en route to medical care. All the horses that fell ill have died.
Veterinarians already at the event quickly tried treating the horses, inserting intravenous lines and trying to cool them down with fans and water. Observers hung blue tarps to shield some of the horses from the crowd's view.
Officials said they have ruled out any sort of airborne infections, and games would resume on Wednesday.
"This was an isolated incident involving that one team," Wash said
The match Sunday was postponed and an exhibition game with a substitute team was held in its place. Because doctors had ruled out an infection, the games will resume Wednesday, Wash said.
Copyright 2009 The Associated Press.