European Hares, , Represent a Reservoir Host for in Romania.

Thelaziosis caused by is an emerging disease in Europe. Only two reports of naturally infected lagomorphs have been published so far. The aim of this study was to evaluate the status of the Romanian populations of European brown hares, as reservoir hosts for . Between November 2019 and November 2021, the eyes of 326 carcasses were examined for the presence of ocular parasites. Nematodes were stored in plastic vials with physiological saline, followed by morphological and molecular identification. QGis 3.20 and EpiInfo 7 were used for mapping and statistical analysis. Four (1.23%) hares harbored infection, with a total of 84 nematodes collected (mean intensity 21 nematodes/host), with 45 males, 39 females (two sexually immature, seven with only eggs, and 30 with eggs and larvae). One specimen from each host was successfully sequenced resulting in a 100% similarity with several other sequences of haplotype 1. Statistical analysis revealed no significant results. The current study represents a first report of in the European brown hare in Romania, and the second in Europe, also reiterating the role of lagomorphs as reservoir hosts for this zoonotic ocular nematode.