Rural dogs (Canis familiaris) as sentinels to ectoparasites and tick borne pathogens around six Atlantic Forest conservation units in Brazil

Abstract

Sentinel hosts are species that are readily observable and more likely than others to be exposed to vector and vector borne pathogens. Surveys of domestic dogs are often utilized to assess tick distribution and tick-borne diseases. Free-ranging habits and poor health management probably increase infectious diseases in rural dogs. The Atlantic Forest biome occurs in some South American countries and is a major center of endemism, highly threatened by deforestation. This study describes the prevalence for ectoparasites and tick-borne pathogens in 323 dogs living at 144 households around six Atlantic Forest conservation units. There were found ticks of the genus Rhipicephalus (11.5 %) and Amblyomma (23.5 %), fleas of the genus Ctenocephalides (44.3 %), Xenopsylla (1.24 %), and Tunga (0.3 %), and lice Trichodectes canis (0,9 %). Blood smear analysis revealed a prevalence of 34.6 % of at least one of the following parasite taxa: Hepatozoon (22.3 %), Babesia vogeli (4.9 %), Ehrlichia canis (3.1 %), and Anaplasma platys (2.8 %). In seven dogs (2.2 %), coinfections were detected microscopically. Serologic tests revealed seroreaction in 47 % of dogs, and the presence at considerable seroprevalence of E. canis (34.3 %), Anaplasma phagocytophilum (23.8 %) and B. vogeli (10.5 %). Serological coinfections were detected in 19.5 % of dogs. The molecular analyses performed using samples from 157 ectoparasites that parasitized the dogs, showed a prevalence of 1.27 % positive for order Piroplasmida, 1.27 % for Ehrlichia spp., 3.82 % for Anaplasma spp., and 22.93 % for Rickettsia spp. The findings highlight the importance of rural dogs as sentinels of diseases for wildlife and humans in Brazil, and the need for straightforward control actions such as treatment against ectoparasites with sufficient coverage, and responsible domestic animal ownership enforcement.