Association between cancer chemotherapy and canine distemper virus, canineparvovirus, and rabies virus antibody titers in tumor-bearing dogs

Objective-To determine the association between cancer chemotherapy and seru m canine distemper virus (CDV), canine parvovirus (CPV), and rabies virus a ntibody titers in tumor-bearing dogs. Design-Prospective study. Animals-21 client-owned dogs with various malignancies and 16 client-owned dogs with lymphoma. Procedure-In study A, serum antibody titers were measured by use of hemaggl utination inhibition (CPV titers) or serum neutralization (CDV titers) befo re and at least I month after initiation of chemotherapy. Baseline values w ere compared with values obtained from a control population of 122 healthy dogs seen for routine revaccination. Titers were considered protective at g reater than or equal to 1:96 for CDV and greater than or equal to 1:80 for CPV. In study B, serum IgG titers were measured by use of immunofluorescent assa y (CDV and CPV titers) and rapid fluorescent focus inhibition test (RFFIT, rabies titers) at baseline and again at weeks 5, 8, and 24 of a standard ch emotherapy protocol for treatment of lymphoma. An IgG titer of greater than or equal to 1:50 was considered protective for CPV and CDV. An RFFIT titer of greater than or equal to 0.5 U/ml was considered protective for rabies virus. Results-Significant changes were not detected in CDV, CPV, and rabies virus titers following chemotherapy in tumor-bearing dogs. Conclusions and Clinical Relevance-Results suggest that established immunit y to CDV, CPV, and rabies virus from previous vaccination is not significan tly compromised by standard chemotherapy used to treat tumor-bearing dogs.