The owners of the 21 polo ponies that died at the U.S Open Polo Championships last year in Wellington, Fla., are seeking more than $4 million in damages from Franck's Pharmacy, the Ocala-based company that mixed the fatal concoction given to the horses.

All the horses that died had been injected with a supplement designed to aid the horses in muscle recovery and which was supposed to contain equal parts potassium, magnesium, and selenium.

State veterinarians determined that the horses died from an overdose of selenium, and Franck's Pharmacy followed with a statement last year that too much selenium had, in fact, been added to the medication.

The horses played for the polo team Lechuza Caracas, owned by Victor Vargas. Members of the lawsuit include teammates Juan Martin Nero, Guillermo Caset, and Nicolas Espain, who together owned nine of the horses; Quorum Management Co., which owned the other 12 horses; and Diamond State Insurance Co., which paid Quorum $1.3 million for the loss of those horses.