The pathology of Mycoplasma hyorhinis arthritis produced experimentally in swine
Roberts, E.D.; Switzer, W.P.; Ramsey, F.K.
American Journal of Veterinary Research 24: 19-31
ISSN/ISBN: 0002-9645 Accession: 025879732
Of the 24 intraperitoneally inoculated pigs, 16 developed varying degrees of lameness at 5 to 12 days postinoculation. Up to 5 joints per pig were affected. The gross appearance of unopened involved joints varied from no visible alteration to a soft, fluctuating distention of the joint capsule. The acute synovial membrane changes consisted of marked hyperemia, edema and, in some cases, fibrin deposits. Histopathologically, these changes were characterized by hyperemia, enlargement of the synovial cells, infiltration of plasma cells, mononuclear macrophages, a few lymphocytes and occasionally neutrophils. The chronic synovial membrane changes consisted of mild hyperemia and hypertrophy of the synovial villi associated with a yellowish coloration of the membrane. Histopathologically, these changes were characterized by hypertrophy of the synovial villi, hyperplasia of synovial cells and lymphocytic infiltration concentrated in nodular foci.