The third metacarpal bones (McIII) of 42 2-year-old thoroughbreds in training were evaluated clinically and radiologically every 15 days. The evaluation was performed during 2 and 4 month, prior to the first race of 25 and17 horses, respectively. X-rays were taken using latero-medial projection. Dorsal cortex (DC) was evaluated on the X-rays and DC, palmar cortex and medular zone were measured in order to determine the radiologic index (RI). No radiographic changes were observed on the DC of the McIII of horses clinically affected by dorsal metacarpal disease (DMD). There was a significant increase (P<0.05) in DC thickness and RI between evaluations of both, healthy and DMD affected McIII. DC thickness also showed a significant increase between affected and not affected McIII. A larger increase in DC thickness was observed at evaluation before the one in which DMD was diagnosed. In conclusion, the increase in DC thickness could be used as a diagnostic tool for early recognition of DMD allowing adoption of preventive measures.
radiograph; third metacarpal bone; dorsal metacarpal disease; horses
