Seroepidemiological survey of Brucella canis infection in dogs in Japan

A seroepidemiological survey of Brucella canis infection was performed on 1,071 dogs (companion, stray, and shelter groups) from seven prefectures in Japan. Overall, 3.5% (38/1,071) of the dogs were seropositive for B. canis by microplate agglutination test although no clinical signs were observed in positive animals. The seroprevalence by dog group was 2.9% (24/835) in the companion group, 3.6% (4/110) in the stray group, and 7.9% (10/126) in the shelter group. A significant difference was found between shelter and companion groups (P < 0.01). Our study shows that asymptomatic infection of B. canis is widely distributed among dogs in Japan, and rearing in a group under poor hygienic conditions may lead to a risk of exposure to B. canis.