Florida Agriculture and Consumer Services Commissioner Charles Bronson has launched an investigation into the deaths of 21 horses that collapsed after arriving in Wellington, Fla., for a polo match. Fourteen horses died by Sunday evening and an additional seven died overnight.

Because of the very rapid onset of sickness and death, state officials suspect these deaths were a result of an adverse drug reaction or toxicity. At this time there is no evidence that these horses were affected with an infectious or contagious disease as there are no other horses affected at this time.

The department’s Division of Animal Industry, headed up by the state veterinarian, is involved in the investigation and the department’s Office of Agricultural Law Enforcement is also participating and working with local law enforcement.

The horses have been transported to a Department of Agriculture lab in Kissimmee, Fla., and to the University of Florida Veterinary School for necropsies and toxicology testing. It could take several days before any test results are in or a cause of death is known