On the pathogenesis of spontaneous parvovirus infection

The internal organs of 21 beagles spontaneously infected with parvovirus were examined histologically and in 10 of the dogs immunofluorescence examination was also performed. The study showed that the pathological process had started in the small intestine and from there the viral agent had spread through the regional lymph nodes into the other lymphatic and the haemopoietic organs causing there depletion predominantly of lymphocytes and arrest of haemopoiesis. Four dogs displayed conspicuous oedema of the media of the arterioli in the liver. In the cytoplasm of probably Kupffer's cells specific fluorescence was present in all the 10 dogs examined. On the other hand neither viral antigen nor histological changes were found in kidneys. Our observations suggest that spontaneous infection of dogs with parvovirus takes place per os. Parvovirus is not eliminated from the organism with urine.