Study on seasonal activity in dogs and ehrlichial infection in Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) from southern Uruguay

the seasonal activity on dogs of rhipicephalus sanguineus in southern uruguay has been studied from samples collected in veterinary clinics of the country. from a total of 744 specimens, adults (92%) were active on dogs between august and march (peaking in october) being absent between april and july. immatures represent more than 80% of captures on dogs in summer. this pattern is well correlated with the climate records in the zone. the search for ehrlichial dna from tick-derived extracts (36 pools from 180 ticks) was negative in all the cases. while r. sanguineus has been incriminated as vector of these pathogens, additional studies are required to understand the role of this tick in the transmission of ehrlichial organisms