Ehrlichia and Borrelia spp. infection in German Shepherd dogs in Korea

The presence of the tick-borne pathogens Ehrlichia and Borrelia in German Shepherd dogs in Korea was determined by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). A total of 291 dogs were randomly selected from five Korean provinces from October 2005 through September 2006. The seroprevalence of antibodies to canine Ehrlichia and Borrelia agents detected by ELISA (Snap® 3Dx® Test, IDEXX Laboratories) was 7.56% (22 dogs) and 1.72% (5 dogs) respectively, throughout the country. Positive antibodies against both pathogens were detected in two dogs (0.69%). The provincial distribution of seroprevalence against Ehrlichia was 1.28% (1 of 78) in Gyeonggi-do, 12.64% (11 of 87) in Gangwon-do, 9.76% (4 of 41) in Chungcheong-do, 8.93% (5 of 56) in Gyeongsang-do, and 3.45% (1 of 29) in Jeolla-do. According to PCR analysis, Ehrlichia chaffeensis target DNA was amplified in 3.09% (9 of 291 dogs) of blood samples, 2.41% (7 of 291) from Gangwon-do and 0.69% (2 of 291) from Chungcheong-do. The oligonucleotide sequences (SNU-EC3 and SNU-EC5) from the PCR fragment examined in Korea were closely related to E. chaffeensis isolated from the tick Haemaphysalis longicornis, in China and the state of Arkansas in the US. Based on these results, the presence of E. chaffeensis infection was identified in German Shepherds being bred in Korea. These results bring to light the importance of paying close attention to tick-borne infections such as Lyme disease during clinical diagnosis. This infectious disease should be included as a differential diagnosis for patients who participate in outdoor activity from spring to fall or who have thrombocytopenia or leucopenia.