Necrotizing meningoencephalitis in pug dogs in Japan.

This report records necrotizing meningoencephalitis in three pug dogs. It is the first record of the disease in Japan. There were three characteristic histopathological findings, namely (1) a non-suppurative inflammatory cell infiltration of the cerebral hemispheres, including both gray and white matter, (2) meningeal and perivascular infiltrates of mononuclear cells, with a strong tendency to invade the underlying or surrounding brain parenchyma, and (3) selective cerebral cortical necrosis, often occurring without a concurrent inflammatory reaction. The three cases, which were diagnosed as pug dog encephalitis, resembled those previously reported in the United States of America, Switzerland and Italy. All affected animals were females with clinical histories of pregnancy or phantom pregnancy 2 weeks or less before the onset of the clinical signs.