In the first study of its kind performed on 2-year-old Thoroughbred racehorses, Daniel T. Meagher, DVM, MS, Dipl. ACVS, of Valley Equine Associates, in Ranson, W.Va., set out to determine the prevalence of radiographic lesions and their effect on race performance. A similar study was previously carried out on radiographic abnormalities in yearlings, but Meagher's study was the first to examine the prevalence of abnormalities in 2-year-olds and what effect they had on their racing careers.

At the 56^th Annual Convention of the American Association of Equine Practitioners, Meagher presented the current study in which he and his colleagues examined carpal, fetlock, stifle, and hock radiographs associated with 2-year-olds in training sales from 1997 to 2001 in Barretts Equine Limited's repository. Barretts, a Thoroughbred auction company based in Pomona, Calif., gave Meagher access to these radiographs for the research.

Of the 953 sets of radiographs examined, 69% (654 horses) had no evidence of lesions and served as controls, and the remaining 31% (299 horses) with lesions were considered cases. Meagher noted that 63% of the case horses were male, and that 11 horses had lesions in more than one region (in both the knee and the fetlock, for example).

Meagher's findings revealed that the case horses were statistically less likely to start a race or earn money. "Eighty-six percent of (case) horses raced, while 91% of control horses raced," he said