Improving the predictability of performance by prerace detection of dorsal metacarpal disease in thoroughbred racehorses

OBJECTIVE: To determine the prevalence of dorsal metacarpal disease in 2-year-old Thoroughbred horses by prerace inspection and to evaluate the effectiveness of a dorsal metacarpal disease detection program on the predictability of race performance (finishing in the order predicted by punters) and the distance between the first- and last-placed horse in a field. DESIGN: A retrospective study using client-owned horses. METHODS: A program of prerace detection of dorsal metacarpal disease using digital palpation of the dorsal aspect of the third metacarpal bone of both forelimbs of 2-year-old Thoroughbreds racing at Ascot racecourse was instituted by the Western Australian Turf Club in December 1995. Horses that had significant pain reaction to digital palpation were considered to have pain due to dorsal metacarpal disease, withdrawn from that day's race and not permitted to race for 6 weeks. The race records of all 2-year-old Thoroughbreds racing at Ascot racecourse from December 1993 until December 1995 were compared with the race results from December 1995 until March 1997, after initiation of the dorsal metacarpal disease detection program. RESULTS: After initiation of the program, horses were racing more predictably over 1100 m (P = 2.09) and 1200 m (P = 3.48). These horses finished closer to the winner over 1100 m (P = 3.39) and over 1200 m (P = 3.13). In 1000 m races, the trend for horses to race more predictably (P = 1.07) and for there to be less distance between first and last (P = 1.72) was not statistically significant. CONCLUSIONS: The program of prerace digital palpation for dorsal metacarpal disease was considered to be beneficial in 2-year-old Thoroughbreds racing over 1100 m and 1200 m, in that they raced more predictably.