Clinical, hematological and pathological findings in specific pathogen-free cats and conventional cats experimentally infected with canine parvovirus.

Abstract

For the purpose of confirming whether the canine parvovirus (CPV) has a pathogenicity to cat or not, 5 specific pathogen-free (SPF) cats and 4 conventional cats were inoculated with CPV. The SPF cats did not show any clinical signs, but the conventional cats showed marked clinical signs, such as depression, anorexia, vomiting and temporary pyrexia, and in one of the conventional cats died on the 4th day post inoculation (DPI). In hematological findings, the SPF cats showed only mild leukopenia, but the conventional cats showed severe one accompanied with neutropenia. In myelograms, a decrease of the total number of nucleated cells including myeloid and erythroid cells was observed. This was marked in the conventional cats. Pathological findings were hemorrhage on the mucosal surface at the small intestine, atrophy of the thymus, and enlargement of the mesenteric lymph nodes. Histologically, atrophy of the intestinal villus, depression of lymphatic tissues and depletion of nucleated cells at the bone marrow were observed. Moreover, intranuclear inclusion bodies were recognized in the intestine, lymphatic tissues and bone marrow. Hemagglutination inhibition (HI) antibody developed rapidly from 3 to 5 DPI and its highest titers were noted on 7 DPI. In addition, CPV were recovered from the intestine, mesenteric lymph nodes, bone marrow and other tissues of both groups of cats autopsied within 5 DPI.