Freund's adjuvant (FA) and TiterMax (TM) were compared for their effectiveness in the induction of the anti-idiotypic antibodies (anti-Id or Ab2) in pigs, goats and mice against swine polyclonal anti-pseudorabies virus (PRV) antibodies (Ab1) by sequential immunization procedures. Both adjuvants had similar effects on inducing anti-swine immunoglobulin antibodies in the animals. However, high levels of the anti-Id were only generated in animals that received FA. Serological characterization of the anti-Id antisera indicated that internal image anti-Id (Ab2 beta) was generated that recognized shared idiotype (IdX) on the antibodies to PRV. The internal image Ab2 was capable of blocking the anti-PRV antibodies from binding to the PRV antigens, and their interaction with anti-PRV antibodies could be inhibited by PRV antigens.