EN
The investigation was performed in the farm where polyarthritis was observed in cattle for the last two years. The farm consisted 106 milkings cows and 250 fattened calves per year. The calves originated partly from the farm and partly have been bought at the market. They suffered mostly from bronchitis and bronchopeumonia. Clinical symptoms of polyarthritis associated with anorexia, growth inhibition and moving discordance appeared in 28 culled fattened bulls. First symptoms of painfulness of the joints have been observed in some animals already 1—2 months after fattening started. Most disorders intensity has been stated at the end of fattening period, when the swelling and deformation in consequence of chronic tissues inflamation, mostly in carpal- and tarsal- then in elbow-, shoulder-, knee- and also hip- joints, developed. Post-mortem findings revealed fibrinous exudate in the joints and degenerative lesions on the surface of joint cartilages. In one living bull, Mycoplasma bovis was isolated from the joint exudate obtained by punction of the carpal joint. Mycoplasma was isolated also from the nasal swabs in 15 amongst 17 collected from 1—20-mont -old animals showing polyarthritis symptoms. The isolation of Mycoplasma and negative results of bacteriological examination indicate the pathogenic role of these microorganisms in enzootic polyarthritis in Poland.