The physiopathological changes in synovial fluid in arthritic swine.

There was produced with Ery. rhusiopathiae a rheumatoid-like arthritis in swine, which passed successively through acute, sub-acute and chronic stages. This was typically a non-suppurative proliferative change with concurrent changes in the joint fluid. The arthritis was shown to persist even though the initial inciting agent could not be isolated from the advanced cases of chronic polyarthritis. This strongly suggests that the pathological process responsible for this arthritis can become autonomic and probably is related to a state of hypersensitivity. The cellular changes observed in the synovial fluid did not differ markedly from those of rheumatoid arthritis in man. Synovial fluid mucinous changes were apparent in the decreased viscosity observed grossly. Definite changes in the character of the precipitate produced by acetic acid treatment of the fluid were also observed.