PubMed1990
In 2 pig farms, 102 sows kept in single ranging on plain concrete floor, 168 sows kept in single ranging on cast-iron grates and 27 fattening pigs kept in group penning on concrete slatted floors were repeatedly examined for the incidence of auxiliary synovial bursae (ASB). The clinical examination was completed by radiological, patho-anatomical and histological examinations of the rear legs. In sows, ASB were found on two prominences of the bones: on the latero-plantar area of the calcaneum and the fourth tarsal bone as well as on the plantar tarsal sesamoid bone. ASB on the rear legs were found in 41.2% of the sows kept on plain concrete floor and in 59.5% of the sows kept on cast-iron grates. The ASB of the sows kept on cast-iron grates were larger than those of the sows kept on plain concrete floor. In 49% of the sows kept on plain concrete floor the skin covering the ASB was reddened, in 45% of the sows kept on cast-iron grates it was covered with scab. Injury and necrosis of the skin as well as injury of the ASB themselves were found only in animals kept on cast-iron grates and made up 5% of the cases. In 30% of the cases, palpation of the ASB induced defensive movement. The palpation of ball-shaped, soft bursae more often caused defensive movement than did the palpation of flat-shaped, hard bursae. The occurrence of ASB was combined with kyphosis of the spine, false posture of the rear legs, dystasia, hyperextension of the fetlock, arthrosis of the ankle joint, and anomalies of the claws. In fattening pigs, the ASB were localized at the lateroplantar area of the calcaneum and the fourth tarsal bone as well as at the posterior surface of the calcaneum. At the end of the fattening period, ASB were detected in 26 out of 27 fattening pigs. All of the 48 ASB that were examined histologically showed signs of inflammation. In 30 cases the inflammation was chronic, in 18 cases it turned out to be florid. The results indicate that ASB cause pain during the developing phase and also in the chronic stage.