Joint changes in lameness of confined swine.

Hampshire swine reared in confinement developed spontaneous lameness. In a comparison of lame swine with normal Hampshire and normal Yorkshire swine, there were no substantial differences in the gross or microscopic appearance of synovial membranes or volume of synovia per joint. Somatic cell count in synovia of lame Hampshires was higher than that of normal Hampshires; however, in normal Yorkshires, cell count was higher than that of either group of Hampshires. Total protein and total lactic dehydrogenase (LDH) values were significantly higher in synovia of lame swine than in synovia of normal swine, as were also the gamma-globulin and LDH5 values. Hampshire swine seemed to be more heavily muscled than the Yorkshires, but the difference was not significant. In a 2nd comparison, joints of the swine were regrouped as normal or abnormal, on the basis of macroscopic appearance. Significant differences were not detected in total volume of fluid per joint, number of somatic cells per milliliter of fluid, total protein, or the 3 microscopic lesion scores in this comparison. Total LDH was significantly higher in the abnormal joints.