The horses were from the Venezuelan-owned Lechuza Caracas team and were valued at approximately $100,000 each. As the horses were being unloaded from their boxes, several fell to the ground. Fourteen of the team of twenty four died within a few hours and seven more died during the night. Because the animals died so quickly after displaying symptoms, vets suspect an adverse drug reaction. It is highly unlikely that the cause was an infectious disease since the deaths were restricted to only one team.
The Florida agriculture department and the local sheriff’s department in Palm Beach County have launched investigations. According to the Associated Press, initial tests have revealed that internal bleeding caused the deaths and are hoping that lab tests will identify a toxic agent. The team leader of the Venezuelan team told a newspaper that the horses were injected with a supplement called Biodyl, which is not approved for use in the US, but is widely used elsewhere. Biodyl is a vitamin and mineral solution containing ATP, selenium and B12. The use of Biodyl is described as for the "Prevention and treatment in case of lack of selenium in calves, lambs, swines, equines, dogs and cats". Given that it is widely used and that the team would be unlikely to try a new supplement just hours before a match, it must be assumed that the supplement itself must have been contaminated with the toxin that caused the deaths.
First played in 1904 at Van Courtland Park, the US Open Championship celebrated its centennial in 2004 and is one of three great polo tournaments, along with the British and Argentine fixtures. Since 1996, The US Open Championship has called Palm Beach, South Florida its home. Championship polo matches are due to resume today (Thursday), four days after the incident.