A veteran jockey who had planned to retire at the end of the year was killed at Belmont Park when his mount broke a leg and the man fell to the track, where he was kicked in the face by another horse. Mike Venezia, the rider of more than 2,000 winners in more than 21,000 races since 1964, died in the fifth race on Thursday's card, officials said. Robbie Davis, the rider of the other horse, was taken to a hospital for treatment of shock. Venezia's mount, a 3-year-old gelding named Mr. Walter K., was humanely killed. Venezia, 43, was the first jockey killed at a New York Racing Association track since March 29, 1982, when Amado Credidio died after he was thrown over the top of a horse onto the ground and into the path of several other horses in a race at Aqueduct. Venezia's mount broke his right foreleg going down the backstretch of a 1 1-16 mile allowance race. Venezia attempted to pull up the gelding, then went off the horse to his left and fell crosswise on the track, directly in the path of the other horse, Drums in the Night. ``I think he was dead when the (ambulance) technician got to him,'' Dr. Leo Skolnik, the examining NYRA physician, said. ``He was apparently kicked in the face. He had no pulse, no respiration and his pupils were dilated and fixed. ``I don't see how a fall to the ground could have sustained this kind of injury.'' The last four races of Thursday's card were canceled. Racing was to resume today and a memorial service was to be held for Venezia, who had planned to retire at the end of this year.