Risk Assessment and Management of Brucella canis Introduction via Commercial Dog Imports Into France.

Canine brucellosis, caused by Brucella canis, is a likely underdiagnosed zoonotic disease that leads to reproductive failure in dogs and economic losses for kennels. Since 2020, cases in mainland France have been on the rise, with most attributed to the importation of dogs from Eastern Europe. However, the risk of introducing B. canis into mainland France through commercial dog imports from worldwide sources remains poorly characterized. To address this gap, a quantitative risk assessment was conducted using a stochastic scenario tree model incorporating the region of origin of the imported dogs. In addition, impact of management measures on the annual number of B. canis-infected dogs imported into France was evaluated. The results showed that the commercial dog imports represent a substantial risk for introducing B. canis into mainland France, with a median annual number of infected dogs imported estimated at 41.60 (95% PI: 5.12-8784.00). This risk was particularly high for imports originating from the USA, Eastern Europe, North Africa, and Latin America. The evaluation of management measures through simulations showed that the introduction of mandatory pre-import testing for B. canis, with 80% compliance or full enforcement-could significantly reduce the associated risk. These measures led to a reduction in the annual number of infected dogs imported into mainland France by a factor of 4 to 1000 compared to the baseline model. These findings highlight the need for implementing targeted management measures to prevent the introduction of B. canis into France.