WELLINGTON, Fla. – The Food and Drug Administration joined state and local investigators Wednesday after a polo captain revealed that 21 horses that mysteriously died in Wellington may have been given a substance banned in the U.S.

Top Lechuza Caracas polo player Juan Martin Nero told an Argentine newspaper the horses that died Sunday and Monday were given a weekly vitamin compound called Biodyl. The mixture, a combination of vitamins and minerals, is not approved in the United States and is illegal to possess or use, according to the FDA.

Though Biodyl by itself is unlikely to have killed the prized horses, veterinary experts say, it may have been part of a deadly, home-brew concoction whose legality could also be in question.

The horses went into distress Sunday at the International Polo Club Palm Beach fields in Wellington. Fourteen died Sunday, the others Monday.

Nero told the newspaper La Nacion that the horses were given Biodyl on Sunday to help them recover from the wear and tear of the polo match.

“We have no doubt about the origin of the problem,” Nero told the newspaper. “There were five horses that were not given the vitamin and they’re the only ones that are fine.”

Siobhan DeLancey, spokeswoman for the FDA’s Center for Veterinary Medicine, said it is illegal to possess or use Biodyl in the United States. FDA records show agents blocked shipments as recently as October because it was “a new animal drug which is unsafe.” FDA agents are working with state investigators, she said.

Steve Dickinson, spokesman for Merial Limited, the French-American company that makes Biodyl, said it is safe and has been used in Europe and Latin America since the 1950s. It is a combination of vitamin B12, selenium, potassium and magnesium.

“We went back many, many years and this product has an exceedingly rare rate of adverse reactions,” Dickinson said. “From our experience, it’s less than one animal in over 2 million doses.”

Biodyl is legal in Venezuela, where the Lechuza Caracas polo team is based. The team declined to comment, through a public relations company.

Investigators at the University of Florida and a state-run lab in Kissimmee are awaiting results from blood and tissue tests after the initial necropsy results were inconclusive, said Terence McElroy, spokesman for the Florida Department of Agriculture and Consumer Services. He said hemorrhaging was found in the horses’ lungs, which was to be expected given the distress they were in. Investigators are also mindful of the reports about Biodyl, he said.

Dr. John Harvey, executive associate dean at the University of Florida’s College of Veterinary Medicine, said the compound by itself shouldn’t have been fatal and preliminary tests for Biodyl’s ingredients so far turned up nothing unusual.

“If it’s done properly, I don’t think it’s going to kill a horse,” Harvey said. “On the other hand, if someone added stuff or made it improperly … those would be the concerns I would have.”

Nero, the polo team captain, hinted at that possibility, saying he thought the horses were given a typical dose Sunday, but whoever mixed or provided the drug may have made a mistake.

“For us, the suspicions are that there was something bad at the laboratory,” Nero said.

Local veterinarians said it is common for pharmacists and vets to mix their own compounds and it would be easy to replicate Biodyl’s formula.

“The drug itself should not be harmful to a horse if mixed properly and given in the proper amount,” said Wellington veterinarian Dr. Ben Schachter, who does not use the drug or any formulation of it.

Dr. Rob Boswell said Biodyl is commonly used worldwide, but not as a performance enhancer.

“(Lechuza Caracas) is a very experienced polo team. They’re not new to this game. They give Biodyl for a very good reason,” Boswell said. “It’s a recovery drug and helps the horses recover from strenuous exercise. It’s used to help these horses, not make them super horses.”

The polo club in Wellington referred questions to the United States Polo Association, which does not have any rules about care for horses outside of actual matches. The association released a statement saying officials would await official test results before commenting on any possible causes of death or new rules.

Thursday afternoon, a memorial is planned for the horses after the 5 p.m. match at the U.S. Open in Wellington. The Lechuza Caracas team, distraught over the loss of their horses, pulled out of the tournament.

“The truth is, it was horrible, horrible,” Nero said. “To put together a team of horses like we had takes years. And to have something like that happen to you is crazy.”

Staff Writers Carlos Harrison and Maria Herrera and Staff Researcher Barbara Hijek contributed to this report.

—

(c) 2009, Sun Sentinel.

Visit the Sun Sentinel on the World Wide Web at http://www.SunSentinel.com

Distributed by McClatchy-Tribune Information Services.

AP-NY-04-22-09 2207EDT