Franck's Pharmacy of Ocala, Fla. released a statement that "the strength of an ingredient in the medication was incorrect."
The pharmacy, which prepared medication for the animals based on an order from a veterinarian, did not name the medication or the ingredient.
However, the Venezuelan Lechuza Caracas Polo team released this statement: "Much attention has been given to BIODYL, an injectable vitamin supplement that is manufactured in France and is used worldwide in horses competing in strenuous competitions such as polo. BIODYL is not the issue in this instance. A Florida-licensed veterinarian wrote a prescription for a compounded substitute vitamin supplement for BIODYL containing vitamin B, potassium, magnesium and selenium. This compound was prepared in the State of Florida by a compounding pharmacy. Only the horses treated with the compound became sick and died within 3 hours of treatment. The horses that were not treated remain healthy and normal."
The horses reportedly appeared dizzy and disoriented while being unloaded from their trailers Sunday afternoon just prior to a 3 p.m. match. Seven died at the scene, and the others during treatment elsewhere or while being moved to a medical facility.
"As soon as we learned of the tragic incident, we conducted an internal investigation that was led by an outside lawyer and, upon its conclusion, we immediately alerted the state Department of Health and Board of Pharmacy," according to a statement from Jennifer Beckett, Chief Operations Officer, Franck's Pharmacy.
Pathologists from the Department of Infectious Diseases and Pathology at the University of Florida College of Veterinary Medicine and UF's Florida Racing Laboratory have been conducting toxicology and other tests on the dead animals, as was the Division of Animal Industry (DAI) in Kissimmee.
Almost immediately, officials indicated it appeared the horses died of heart failure caused by a toxin that could have tainted their food, vitamins, supplements or all three.
Tests were to determine the drug responsible.
Peter Rizzo, executive director of the United States Polo Association (USPA), said in a media release that the news reports of the pharmacy admitting to wrongly preparing the medicine before last Sunday's match is very disheartening.
"We have all suffered a terrible loss," he stated. "Today we come together to celebrate our sport with our championship matches and tonight we will come together again to mourn our fallen ponies in a memorial service. We will continue to work with all the authorities to get to the bottom of this tragedy and determine definitively what happened to the horses in this isolated and unprecedented event."
While Franck's plans to continue its cooperation with the investigation, because it is ongoing, Beckett states "we cannot discuss further details about this matter at this time."