| Abstract: | Sixty weanlings were maintained in dry lots without forced exercise and individually fed a diet consisting of 25% Bermudagrass hay and 75% balanced concentrate twice dally. Radiographs of the carpus, metacarpus and first phalanx, and other radiographs of the tarsal region, were taken initially at approximately 180 d of age and at approximately 236, 292 and 348 d of age. The radiographs were evaluated for the presence or absence of subchondral and/or cystic lesions in the carpal and tarsal regions and for closure of physes of the distal third metacarpus and proximal first phalanx. Physeal scores were: 1 = open; 2 -- partially closed; 3 = closed. Only 1.7% of the horses had subehondral lesions in the carpal region at 180 d, and none had those lesions at 236, 292 or 348 d. There was a 3.3% incidence of subchondral lesions of the tarsus at 180, 236 and 292 d, but only 1.7% at 348 d. Cystic lesions of the carpus were evident in 13.3% of the horses at 180 d, 16.7% at 236 d and 18.3% at 292 and 348 d. None of the hrses had cystic lesions oftbe tarsus at 180, 236 or 348 d, but 1.7% had them at 292 d. Physeal closure scores for the distal metacarpus averaged 1.5 and 2.6 at 180 and 236 d, respectively. At 292 and 348 d, all of the distal metacarpi were closed. Physeal closure scores for the proximal first phalanges were 1.5, 2.6 and 2.9 at 180, |
