Radiographic diagnosis of hereditary chondrodysplasia in newborn lambs.

Normal appearing Suffolk lambs affected with hereditary chondrodysplasia (HC) and normal appearing unaffected lambs were radiographed at birth, and at 2, 4, and 8 weeks of age. In affected lambs, lesions were seen consistently in the elbows, shoulders, sternum, and spine. Similar lesions were not identified in unaffected lambs. A malformed Corriedale lamb was radiographed to compare its lesions to those seen in HC. The Corriedale lamb had islands of ossification of the anconeal process similar to those identified in lambs with signs of HC at birth. The islands of ossification seen in the Corriedale lamb were fused by 2 months of age, whereas elbow lesions seen in lambs with HC increased in severity during the same period.