The objective of this research project was to investigate the reasons associated with the premature retirement of Thoroughbred horses in training at the Hong Kong Jockey Club (HKJC) and to develop intervention strategies in an attempt to reduce training and racing ",. injuries. The impetus for this project was a survey aimed at identifying the reasons for a decline in the race attendance and betting revenue. This identified premature retirement and an increase in turnover of horses which reduced the opportunity to "get to know" individual horses as one of the reasons for the decline. Content analysis of reasons for retirement identified superficial digital flexor (SDF) tendon injury as the major reason for the premature retirement in this population accounting for a mean of 3.2% of the total. The mean annual cumulative incidence of retirements due to SDF tendon injury was 3.2% accounting for 14% of all retirements. A follow up descriptive analysis of retirement of Thoroughbred racehorses due to tendon injuries at the Hong Kong Jockey Club (1992-2004) provided population based data on the frequency, career and economic losses associated with tendon injury induced retirement. The risk of tendon injury increased over the 12 year period from 2.3-4.2%. The length of the racing career, number of starts and earnings of horses retired with tendon injuries were reduced by 25.6,41.2 and 53.3%, respectively. Further evaluation of detailed training data (1997-2004) to identify risk factors for retirement because of tendon injuries in Thoroughbred racehorses was undertaken. Conditional logistic regression analyses were performed to identify risk factors for retirement from racing attributable to tendon injury.