Production of arthritis by intravenous inoculation of Mycoplasma hyopneumoniae: tests on five strains.

Cultures of five strains of Mycoplasma hyopneumoniae (syn, M suipneumoniae) were each inoculated intravenously into four pigs aged eight to nine weeks. One strain produced no response. For two strains two of the four pigs showed complement fixing antibody and mycoplasmaemia and one of these pigs in each group developed arthritis in one limb joint. The response to the other two strains was more severe: all four pigs in each group had a serological response, were mycoplasmaemic and several limb joints were arthritic.