Ehrlichia canis infects monocytes and is the causative agent of canine ehrlichiosis, which is a serious and potentially fatal disease of dogs. However, the epidemiology of E. canis on mainland Turkey remains unclear.
Therefore, dot-ELISA and indirect fluorescent antibody (IFA) testing was used to survey for the presence of antibodies against E. canis in blood samples of 208 dogs that harbored ticks from the Mediterranean region of Turkey. The dogs were examined physically and peripheral blood smears were made and stained with Giemsa and examined microscopically. Although, 91 (44%) of the dogs were showing the clinical signs of E. canis infection, 117 (56%) of the dogs were not showing any clinical signs of E. canis infection but physical observations concerning tick infestation (with Rhipicephalus sanguineus) were positive.
Antibodies reactive with E. canis were detected in serum by dot-ELISA (titer > 1:20 accepted positive) and IFA tests. Of 208 dogs examined, 136 (65%) and 154 (74%) dogs showed positive findings in dot-ELISA and IFA testing, respectively. A higher seropositive reaction to E. canis was observed in the 117 clinically normal dogs, ELISA 90 (77%) and IFA 98 (84%). Of 91 clinically diseased dogs, 46 (50.5%) and 56 (61.5%) were positive in ELISA and IFA testing, respectively. None of the dogs with serological evidence of ehrlichiosis had typical E. canis morulae detectable in blood smears. Neither sex nor age was associated with the seropositivity of E. canis (P >0.01).
Results suggest that E. canis circulates in dogs in Turkey and it is transmitted by the brown dog tick Rhipicephalus sanguineus. E. canis infects dogs without age or sex predilection and infected carrier dogs also may play an important reservoir role in Turkey.