HISTOPATHOLOGICAL FEATURES OF CANINE-DISTEMPER RECENTLY OBSERVED IN JAPAN

Eleven dogs with canine distemper (CD) from the Chubu region of Japan and the Tokyo area were examined. Clinically, respiratory and neurolog ical signs were present in all animals. Histopathologically, all showe d characteristic CD lesions of bronchopneumonia and demyelinating ence phalitis. However, some differences in gastrointestinal abnormalities were observed. Three out of four dogs from the Chubu region had severe diarrhoea and gastroenteritis, associated with numerous eosinophilic inclusion bodies in the mucosal epithelia. The remaining dog from this area showed vomiting, but not diarrhoea, and also had a number of int raepithelial inclusion bodies in the gastric and intestinal mucosa. In contrast, the seven dogs from the Tokyo area showed neither gastroint estinal symptoms nor intraepithelial inclusions in the stomach or inte stine. Immunohistochemical examination for CD virus antigen, however, revealed that these seven dogs had immunoreactive products in the muco sal epithelia, suggesting that the epithelial cells had either a low l evel of infection with CD virus or were infected with a less cytopatho genic virus. These findings suggest that the dogs in this study were p robably affected by two distinct types of CD, in terms of epitheliotro pism and cytopathogenic effects on the gastrointestinal tissues. (C) 1 997 W.B. Saunders Company Limited.