Reports of Lipoptena fortisetosa on dogs and in the environment, and evidence of its widespread establishment in Hungary

Lipoptena fortisetosa is a louse fly of East Asian origin that is considered a potential vector of several pathogenic bacteria and is most commonly associated with deer (Cervidae). The species has been detected in multiple countries in Europe; however, its exact distribution range is unknown. A single individual was detected on a dog at a veterinary clinic in Budapest, Hungary, a country where the presence of L. fortisetosa has not yet been confirmed. After acquiring information regarding the recent whereabouts of the dog, targeted louse fly collection with insect nets was performed in a forest in Central Transdanubia. Of the 30 flying, unfed specimens of Lipoptena spp., 23 were morphologically identified as L. fortisetosa . Following this, louse fly collections have been conducted across Hungary during the fall of 2025. According to these results, L. fortisetosa can be considered widespread in the country, and that this parasite can be effectively transported by dogs. The findings draw attention to the potential medical and veterinary significance of the emergence of novel vectors that may have been introduced through animal transport.