Mycoplasmal arthritis and meningitis in calves

A disease entity slightly different from, and appearing at an earlier age than, the syndrome known as mycoplasmal pneumo-arthritis was diagnosed in sucking calves. The disease, which had probably originated from intrauterine infection and manifested itself as polyarthritis occasionally accompanied by meningitis, caused huge economic losses due to a substantial reduction of the calf crop on the farm involved. Severe clinical signs were often observed already in the first days after birth. Besides an elevated body temperature reaching 40-41 degrees C, the affected calves showed striking deformities which made most of them unable to stand up or suck; as a result, they became emaciated and died at an age of 1-3 weeks. The gross pathological picture was dominated by serofibrinous arthritis involving several joints. In the articular cavities a large volume of straw-coloured, transparent synovial fluid accumulated which contained thick, confluent, white fibrin films. In some cases a similar exudate was observed in the thoracic cavity, pericardium and cerebral ventricles, too. Histopathological examination revealed serofibrinous inflammation of the synovial membrane of the joints, the pericardium, the pleura, the leptomeninges and the ependyma lining the cerebral ventricles. Our diagnosis was confirmed by the electron-microscopic detection of mycoplasmas from the pathologically altered organs and the isolation of a pathogen identified as Mycoplasma bovis.