Serological investigation of seven zoonotic pathogens in companion dogs in South Korea, 2018-2021

Based on the current situation of Korean culture and society, the population of companion animals in South Korea is growing rapidly along with zoonotic risks. The current data regarding zoonotic infections in companion dogs reported in Korea is sparse. This study aims to investigate the seroprevalence of seven potential zoonotic pathogens in companion dogs in South Korea: Anaplasma phagocytophilum, Borrelia burgdoferi, Ehrlichia canis, Coxiella burnetii, Brucella canis, Leptospira spp. and canine influenza A virus. A total of 284 serum samples were collected from 2018 to 2021, and the immunoglobulin G (IgG) antibodies against 7 zoonotic pathogens were detected using enzyme-linked immunosorbent assays. Samples were divided into five groups and analysed based on age. IgG antibodies against six of the seven pathogens were detected. The highest seropositivity rate was detected for canine influenza A virus exposure (59.1%) for which the rates were the highest in dogs under 1 year old and declined with age. Positivity rates of the other pathogens were relatively low: 1.76% for Leptospira spp., 1.40% for A. phagocytophilum and E. canis, 1.06% for B. canis and 0.35% for B. burgdoferi. No antibodies against C. burnetii were detected in this study. The exposure of dogs in South Korea to six zoonotic pathogens was serologically confirmed, highlighting a potential risk for human infection. The zoonotic risk of companion dogs cannot be neglected, and implementation of One Health approach should be advocated to establish effective preventive measures.