TALLAHASSEE, Fla. — Florida State Veterinarian Thomas J. Holt reported an overdose of selenium was the probable cause of death of the 21 polo horses that collapsed prior to a competition in Wellington April 19.
In a memorandum to Florida Agriculture and Consumer Services Commissioner Charles H. Bronson’s office, Holt stated the animals had “significantly increased selenium levels” in samples tested.
He reported the findings obtained at the department’s Animal Disease Diagnostic Laboratory in Kissimmee were confirmed by independent testing conducted at the University of Florida’s College of Veterinary Medicine in Gainesville, the University of California, Davis’ Animal Health and Food Safety lab and at testing facilities at Cornell University in Ithaca, N.Y.
The three universities assisted in the laboratory testing.
Selenium is a trace mineral which is essential for normal cell function and health in animals and is often included in small quantities in supplements and feed for horses. Large doses, however, can be fatal to animals.
Commissioner Bronson noted the deaths of the horses have triggered an investigation by a number of state agencies, including the Department of Agriculture and Consumer Services and he emphasized the inquiry is ongoing.