Immunity ticks Rhipicephalus sanguineus (Latreille) in crab-eating-fox Cerdocyon thous (Linnaeus) and mongrel dogs

Abstract

Many parasite-host relationships are characterized by the development of resistance by the host, thus limiting the number of parasites. However, in the domestic dog X Rhipicephalus sanguineus (brown dog tick) relationship, this does not occur. The hypothesis that the domestic dog has lost this faculty, following the process of its domestication, was investigated by comparing the mongrel dog’s and the crab-eating-fox Cerdocyon thous's capacity of acquiring immunity to R. sanguineus ticks in two situations: after, 3 successive infestations with adult ticks, and immunisation with an unfed whole tick R. sanguineus extract, followed by a challenge infestation with the same tick species. Evaluation of resistance acquisition, in both experimental conditions, was based on nutricional and reproductive performaces of the female ticks during and after infestations. The results showed a small, significant difference between the domestic dog and the crab-eating-fox. Nevertheless, these differences were not considered relevant enough to characterize an effective immunity.