Osteochondrosis and arthrosis in pigs. II. Incidence in breeding animals.

Joint and bone lesions in Norwegian breeding pigs are described on the background of an investigation involving 174 sows and 155 boars from 7 months to 4½ years old. Lesions, which consisted predominantly of arthrosis, degeneration of intervertebral discs, spondylosis and epiphyseal separations, were demonstrated frequently in both sexes. Osteochondrosis, a condition previously demonstrated frequently in slaughter pigs, had either completely healed, undergone repair or developed into an arthrosis by the time the animal reached an age of about 1½ years. Whereas a higher incidence of arthrosis of the intervertebral joints was found in boars than in sows, the reverse was true as regards degeneration of the intervertebral discs and anchylosing spondylosis. Possible reasons for this are discussed. Norwegian pigs show a higher incidence of lesions in the lumbar region of the vertebral column than has been described up to the present time in other countries.