Synthetic peptides, recombinant fusion proteins and mouse monoclonal antibodies were used to delineate a B cell epitope of the VP'2 structural protein of canine parvovirus (CPV). Although this epitope is not preferentially recognized in the normal antibody response to CPV, virus-specific antibodies could be induced in BALB/c mice with a synthetic peptide representing the epitope. The potential of this non-dominant B cell epitope to induce antiviral immunity in the presence of maternal CPV-specific antibodies, is discussed.