The transmission dynamics of Ehrlichia canis by Rhipicephalus sanguineus ticks

Abstract

Silicone membranes have been used in this study to feed Rhipicephalus sanguineus ticks in an in vitro feeding system. The objective was to obtain high attachment rates so that the transmission dynamics of Ehrlichia canis could be studied. In the acquisition feedings the ticks were fed with blood infected with E. canis. The transmission feedings following the acquisition feedings were used to determine if E. canis transmission to uninfected blood could be established. The results of this study show that E. canis can be transmitted within 17 hours. Further research is needed to determine the minimum time required for transmission.

The same in vitro feeding system was used to study Babesia canis and Babesia vogeli transmission using Dermacentor reticulatus and R. sanguineus ticks respectively. Transmission of B. vogeli could not be established. B. canis transmission could however be established within 24 hours in vitro, but only after pre-feeding the ticks on rabbits before entering them in the in vitro feeding system.

During the E. canis in vitro feeding trials another Rickettsia spp. was transmitted. This Rickettsia spp. appeared already present in the ticks that were used for the in vitro feeding trials. Despite the use of several Rickettsia probes the exact species could not yet be determined.