Comparison of systemic and local immunity in dogs with canine parvovirus gastroenteritis.

To determine whether resistance to canine parvovirus (CPV) gastroenteritis is mediated by local or systemic immunity or both, an enzyme-linked immunospecific antibody assay (ELISA) was developed that quantitated different classes of antibody to CPV. Antibody levels in serum and feces of dogs with CPV-associated gastroenteritis were compared with their clinical signs and viral hemagglutination (HA) titers. Dogs with high levels of CPV coproantibody had a favorable clinical prognosis, high serum antibody levels (hemagglutination inhibition [HI] and ELISA), and low viral HA titers in feces. Conversely, dogs with little or no detectable CPV coproantibody had severe clinical signs and associated mortality rates and high viral HA titers in feces. Many of these dogs had high HI antibody titers. Statistical analysis revealed that only coproantibody level correlated (inversely) with HA titer; serum antibody, whether measured by HI or ELISA, did not. These data suggest that local intestinal immunity is more important than humoral immunity in developing immunological resistance to CPV gastroenteritis.