Jo Jo Cool was euthanized humanely at Tampa Bay Downs on Saturday, after suffering injuries in a spill in the third race.
In the incident, coming around the turn, Jo Jo Cool tossed rider Jonathan Gonzalez. Horn Buckle tossed his jockey Jesus Rios, but continued on to finish the race.
Rios was examined at a hospital, and according to track officials was not seriously injured.
Gonzales is being examined for an ankle injury at St. Joseph's Hospital in Tampa.