Single and co-infections by Anaplasma platys, Babesia vogeli, Ehrlichia canis, and Hepatozoon canis in dogs from Rio Grande do Norte, Brazil: frequency and molecular characterization.

This study investigated the presence of Anaplasma platys, Babesia vogeli, Ehrlichia canis, and Hepatozoon canis in dogs in Mossoró, Rio Grande do Norte, Brazil, from October 2022 to August 2023. Blood samples were collected from 181 dogs with suspected hemoparasitoses based on clinical and/or laboratory findings (such as hematological alterations) for direct hemoparasite examination on slides, polymerase chain reaction (PCR), and phylogenetic analysis. PCR revealed that 72.3% of dogs were infected with at least one agent. Among these, 44.7% were monoinfected and 27.6% coinfected, with 21.5% infected by two agents and 6.1% by three or more. E. canis was most frequent (41.9%), followed by H. canis (35.4%), A. platys (21.5%), and B. vogeli (7.7%). Anaplasma and Ehrlichia-like morulae, Hepatozoon sp. gametocytes, and Babesia sp. merozoites were found in 20.0%, 11.1%, 15.0%, and 1.7% of animals, respectively. Phylogenetic analysis of 16S and 18S rRNA gene sequences revealed high similarity to reference strains from Brazil and other countries. The infection patterns underscore the importance of diagnostic and preventive measures to safeguard animal health in areas endemic for Rhipicephalus sanguineus sensu lato (s.l.), given the frequency of coinfections that may exacerbate clinical signs and hinder treatment.