Discipline: Veterinary Medicine
Blood specimens from dogs in South-West Japan were tested for Ehrlichia canis infection using immunofluorescent antibody test (IFA) and polymerase chain reaction (PCR) based on16S rRNA gene. By IFA, 19.2% (186/968) and 2.8% (11/399) of specimens from stray dogs in Okinawa and Kagoshima prefectures, respectively, were positive. For pet dogs in Okinawa and Tokushima prefectures, l0.9% (12/110) and 2.3% (8/341), respectively, were positive. Among dogs infected with E. canis in Tokushima prefecture, no significant difference was observed between Babesia-positive and Babesia-negative animals. Of IFA-positive specimens from stray dogs in Okinawa and Kagoshima prefectures, 4.3% and l9.1%, respectively, were positive for E. canis using PCR. These specimens were negative by E. muris and E. platys by PCR the base sequences of partial E. canis 16S rRNA gene (389-bp PCR products) from four dog specimens were identical to that observed from a dog in Guangzhou, China. The sequence of 16S rRNA was considered to be needed for the diagnosis of E. canis infection in Japan.