Abstract
At a farm in Chiba Prefecture, in October 1996, an 18-month-old black Japanese heifer introduced from Hokkaido frothed abundantly at the mouth and showed nervous symptoms. Pathological investigation revealed perivascular cuffing, actively proliferating glia cells, and neuronophagias in the cerebrum. The lesions were present but relatively mild in the spinal cord. Immunoperoxidase staining showed the specific Japanese encephalitis virus (JEV) antigen in degenerated nerve cells. In addition, pathological findings indicated that the lungs were affected by fibrous pleuropneumonia. JEV was isolated from the brain and Pasteurella haemolytica from the lung. Two of four heifers reared in the same shed showed a significant rise in the hemagglutination-inhibiting antibody titer to JEV.
