Absence of <em>Brucella canis</em> Detection in Dogs from Central Italy: Implications for Regional Surveillance and Zoonotic Risk

Background: Brucella canis is a zoonotic pathogen associated with reproductive disorders in dogs and represents an emerging public health concern. Dogs are the only known source of infection for humans, and transmission is often associated with close contact, particularly in occupational settings. Reports of canine and human infections in Europe are increasing, underscoring the need for integrated surveillance to assess the risk of introduction and spread. Objectives: This study aimed to estimate the prevalence of B. canis in dogs from Central Italy, a region potentially at risk due to several factors. Methods: A comprehensive serological, molecular, and bacteriological survey was conducted on 128 dogs of various origins, including strays, blood donors, breeding dogs, dogs accompanying refugees, and dogs previously linked to a B. canis outbreak. Blood samples were tested using bacterial culture, real-time PCR, serum agglutination test, complement fixation test, and indirect immunofluorescence antibody test. Results: All tested dogs were negative for B. canis, with an estimated maximum prevalence of 3.5% (95% confidence interval), suggesting a low likelihood of infection within the sampled population. Conclusions: Although no positive cases were detected, maintaining an active and continuous surveillance system is essential to prevent B. canis introduction, particularly through international dog movements and other high-risk scenarios. As dogs represent the only known source of human infection, veterinary surveillance plays a pivotal role in mitigating zoonotic risks. This study highlights the importance of regional surveillance, particularly in low-prevalence areas, as part of broader efforts to support evidence-based control strategies within a One Health framework.