a1 Department of Zoology, University of Edinburgh
a2 Institute for Research on Animal Diseases, Compton
a3 Rowett Research Institute, Bucksburn, Aberdeen
On three occasions, antibody positive blood from wild red deer produced overt infections with Babesia when inoculated into splenecto-mized red deer. One of the deer also became infected with Eperythrozoon sp. Babesia divergens, B. capreoli and the Babesia of red deer are morphologically similar and the marginal position of the parasites in the host cell is characteristic. Babesia were not seen and no antibody was formed in five out of six splenectomized bovine calves which were injected with parasitaemic red deer blood. Two of these calves when challenged with B. divergens were fully susceptible. A transient infection with the deer Babesia may have occurred in the sixth calf since antibody was detected and the animal resisted challenge with B. divergens.In indirect fluorescent antibody tests there was little or no difference in the titre of sera from naturally or experimentally infected cattle and deer when reacted with B. divergens or the red deer Babesia antigens. Despite their similarities, specific status for B. divergens and the red deer Babesia is probably justified; at present there is insufficient evidence to justify separation of the red deer Babesia from B. capreoli.
(Received November 17 1975)