Serologic and hematologic response of rabbits to Anaplasma marginale-infected bovine erythrocytes

New Zeland White rabbits inoculated with Anaplasma marginale-infected bovine erythrocytes produced specific humoral antibodies to this parasite. Specific antibody production as measured by the card and complement-fixation (CF) tests was maximal in 7 to 21 days after inoculation; however, none of the rabbits became infected. Geometric mean CF titers of rabbits inoculated with RBC from cattle with acute anaplasmosis were significantly higher (P less than 0.001) than those of rabbits given RBC from normal cattle. Significant difference was not seen between geometric mean CF titers of rabbits given RBC from carrier cattle and those of rabbits given RBC from normal cattle. It is concluded, therefore, that rabbit inoculations cannot effectively be substituted for calf inoculations to determine the anaplasmosis status of carrier cattle.