Abstract
Clinical and pathological investigations were performed to determine the cause andpathogenesis of periarthritis in dairy cows. Lesion prevalence rate was 24.6%. Hind limbs were affected more frequently than forelimbs. Located on the dorsal sides of the carpal joints and on the external sides of the tarsal joints, lesions were characterized by abrasion, swelling, induration, fluctuation, and wounds. Cysts or abscesses in subcutaneous tissues were not connected with the articular cavity. Cyst exudate was obviously different in quality from synovial fluid. The CD4/CD8 ratio of mononuclears from peripheral blood isolated from cows affected with severe tarsal periarthritis was significantly higher than the corresponding ratio in healthy cows (P<0.05). The IgG1 concentration and the IgGl/IgG2 ratio in cows affected with severe tarsal periarthritis were significantly lower than those of healthy cows (P<0.05). On the basis of these findings, we concluded that the cysts had been induced by persistent or repeated physical pressure on the affected sites and that onset of periarthritis is closely related to dairy-cow management.
