Osteochondrosis and arthrosis in pigs. I. Incidence in animals up to 120 kg live weight.

Joint and bone lesions in growing pigs are described on the basis of post-mortem examination of 341 gilts, boars or castrates from 10 to 120 kg live weight, and 869 separate bones from pigs between 80 and 115 kg live weight at slaughter. No evidence of rickets or generalized osteodystrophia fibrosa was found. Lesions occurred in both sexes. The typical osteochondral lesions were most often symmetrical, occurred at certain sites in joints and epiphyseal plates and were most obvious in the elbow and stifle joint, and in the distal epiphyseal plate of the ulna. Lesions of varying degree could be demonstrated in most pigs at 90–100 kg live weight. The use of the diagnosis osteochondrosis is suggested for local primary non-inflammatory disturbances which lead to a failure of endochondral ossification in joint cartilage as well as in epiphyseal plates. The diagnosis arthrosis is used when the superficial layer of the joint cartilage is affected. Investigations of the early changes in the medial condyle of the femur suggest that the osteochondral lesions start in the deep layers of the joint cartilage. Arthrosis occurred frequently in the lumbar intervertebral joints of Norwegian pigs. Otherwise the lesions appeared to be identical with those described from other countries.