Vector-borne pathogens in dogs and in Rhipicephalus sanguineus sensu stricto ticks in Morocco

Abstract

Canine vector-borne diseases (CVBDs) are of major concern in veterinary medicine worldwide. Amongst the arthropods transmitting CVBD-causing pathogens, the brown dog tick (Rhipicephalus sanguineus sensu lato) is an important vector of agents, such as Babesia vogeli, Cercopithifilaria spp., Ehrlichia canis, Hepatozoon canis, and Anaplasma platys. While data on CVBDs transmitted by Rh. sanguineus s.l. are limited in Morocco, Leishmania spp., transmitted by phlebotomine sand flies, are known to be endemic in several regions of the country. In this study, we investigated the occurrence of tick-borne pathogens (TBPs) (i.e., Anaplasma spp., Babesia spp., Ehrlichia spp., Hepatozoon spp., Rickettsia spp.), Leishmania spp. and filarioids in shelter dogs and their ticks in central Morocco. Blood samples were collected from 144 dogs, and 5,363 ticks were removed from 314 dogs of the same population. DNA samples extracted from blood and from 276 ticks (divided into 55 pools) were screened for selected pathogens by PCR and DNA sequencing. Ticks were morphologically identified as Rh. sanguineus s.l., and molecular analysis of 10 representative specimens confirmed them as Rh. sanguineus s.s. Out of 144 dogs tested, 78 (54.1 %) scored positive for at least one pathogen, with 15 (10.4 %) being co-infected. H. canis was the most prevalent pathogen (38.2 %, 55/144), followed by L. infantum (15.3 %; 22/144), A. platys (5.6 %; 8/144), B. vogeli and E. canis (2.8 %; 4/144). Tick DNA pools scored positive for H. canis (36.4 %; n = 20/55). All dogs tested negative for filarioids and Rickettsia spp. Data herein reported demonstrate a high overall prevalence of CVBD-causing pathogens in dogs from central Morocco, with the unprecedented report of H. canis in dogs and ticks in this country.