Seroprevalence of Leptospiral Infection among Attended Dogs in Taiwan

Our objective is to investigate the seroprevalence among owned dogs from veterinary clinics in Taiwan. Three hundred and thirteen sera of dogs visiting clinics were collected from Feb to Oct. 2003. Questionnaires of each dog were requested at the same time. The carrier state was detected from urine by culture and polymerase chain reaction. The results came out all negative. The anti-Leptospira antibody titers examined with microscopic agglutination test gave an overall seropositive (≧1:100) rate 23.0% (72/313). The rates of individual serogroups were Leptospira interrogans Canicola 16.0%, L. interrogans Icterohaemorrhagiae 15.7%. L. santarosa Shermani 2.6%. L. interrogans Pyrogenes 1.3%, L. interrogans Bataviae 1.0%, L. interrogans Pomona 0.3%, L. bargpetersenii Javanica 0.3%, L. borgpetersenii Tarassovi 0.3% and L. interrogans Australis 0.3%. We found 47.0% dogs were vaccinated within a year based on the questionnaires analyzed. The seropositive rate of vaccinated dogs is significantly higher than non-vaccinated dogs (P ＜ 0.01). We may consider the presence of leptospiral antibodies in owned dogs in Taiwan was mostly caused by vaccination.