Immunity of dogs against Babesia canis, its vector tick Dermacentor reticulatus, and Ixodes ricinus in endemic area.

Previous epidemiological studies allowed us to accurately define endemic areas of canine babesiosis and tick distribution in southeastern France (Martinod, 1983). Using a micro-ELISA test 100 dogs sera were tested with 3 antigens: Babesia canis, Dermacentor reticulatus and Ixodes ricinus. Antibodies against B. canis and its vector D. reticulatus were detected in an endemic area, sometimes with high levels (optical density 1.38 and 0.80 respectively). A correlation factor and regression lines were found between ELISA activity of B. canis and vector tick antigens, even for dogs which never showed any babesiosis symptoms. These results were compared with those of an area without any babesiosis. Furthermore I. ricinus antigens detected ELISA activity in sera of dogs; some cross reactions were observed between I. ricinus and D. reticulatus antigen.