| Abstract: | Systemic and local immune responses were evaluated in dogs given infective canine parvovirus (CPV) and 2 administrations of inactivated CPV 6 months later. Before the inactivated CPV was given, a jejunal cannulation was performed on the animals. During infective CPV administration, concentrations of class-specific copro- and sero-immunoglobulin (Ig)G, IgA, and IgM were determined by enzyme-linked immunosorbent assay. High concentrations of both copro- and sero-IgM, as well as a moderate increase in the concentrations of sero-IgG and copro-IgA, were detected within 3 days after experimental challenge. Hemagglutination inhibition titers correlated with both serum anti-CPV IgG and IgM early and serum anti-CPV IgG in the later states of infection. After 2 oral administrations of inactivated CPV, class-specific jejuno-, copro-, and sero-IgG, IgM, and IgA anti-CPV antibodies also were determined by enzyme-linked immunosorbent assay. High concentrations of jejuno-IgM and moderate levels of jejuno-IgG and IgA were found. Copro-IgM was not detected in the feces; however copro-IgG and IgA were. Also, no correlations were found to exist when sero-IgM and IgG were compared with jejuno- and coproantibody concentrations throughout the experimental period. Thus, it appears that the immune responses to CPV include both a secretory component of the intestinal mucosa and a systemic component of peripheral lymphoid tissues. Application of the modified Witzel's enterostomy to this study of local intestinal immunity proved beneficial. The technique was well tolerated by experimental animals and allowed for simple, multiple sample collections of intestinal contents for virus and antibody determinations with apparently minimal alterations in the luminal environment. |
