The source of a recent West Nile virus infection in a horse in the Netherlands is unclear, as it had been in both Grafschaft Bentheim and the Netherlands recently. West Nile virus is spread by birds and transmitted by mosquitoes to horses and humans, although horses cannot further spread the virus. In recent years, the virus has spread from southeastern Europe towards Central and now Northwestern Europe, including the Netherlands. So far, there have been no human or horse cases of West Nile virus in the Netherlands in 2023, but active monitoring of the virus in horses started in 2021.