Serological and molecular detection of pathogenic Leptospira in shelter dogs in Okayama and Yamaguchi Prefectures, Japan.

Leptospirosis is a zoonotic disease that poses public health risks associated with stray and shelter dogs. We examined Leptospira infection in shelter dogs from Okayama and Yamaguchi Prefectures, Japan, using serological and molecular approaches. Anti-Leptospira antibodies were detected by microscopic agglutination test in 48% (10/21) of dogs from Okayama and 49% (24/49) of dogs from Yamaguchi, with serogroup Hebdomadis predominating. Pathogenic Leptospira DNA was detected in urine samples from two of 12 dogs; both were asymptomatic and infected with Leptospira interrogans ST36 belonging to serogroup Hebdomadis. Given that stray dogs are commonly sterilized and rehomed in Japan, these findings highlight potential transmission risks to veterinarians and adoptive households and underscore the need for management strategies to reduce zoonotic transmission.