The risk of severity of limb injuries in racing thoroughbred horses.

A retrospective study was carried out to identify factors which predisposed Thoroughbred horses to severe injuries, as compared to less severe injuries, while racing on New York Racing Association (NYRA) tracks during the period of January 1986 to June 1988. A severe injury was defined as an injury which led to humane destruction of the horse. A less severe injury was defined as a horse which didn't race within 6 months following a muscular, ligament, tendon, or skeletal injury on the racetrack. The data were obtained from the Horse Identification Department records kept by the Chief Examining Veterinarian of NYRA and included 55 severely injured horses and 245 less severely injured horses. Multiple logistic regression analysis was used to identify factors associated with the risk of severe injuries compared to less severe injuries in those horses. There was a significant association between track and the risk of severe injury (horses raced on Belmont and Saratoga were more likely to develop a severe injury compared to horses raced on Aqueduct Main). The track surface was also associated with the risk of severe injury (horses raced on a firm turf had a significantly lower risk of severe injury associated with the track was significantly modified by the track condition (horses raced at Belmont when it was muddy had a significantly increased risk compared to Aqueduct dirt). Horses were more likely to experience severe injury in the early part of the race (less than or equal to 6 furlongs) than the latter part of the race (greater than 6 furlongs). The risk of severe injury decreased with the age of the horse.