Ophidiomycosis in Wild Dice Snakes (Natrix tessellata) in Germany

Ophidiomycosis (formerly snake fungal disease) is an emerging disease in snakes caused by the fungal pathogen Ophidiomyces ophidiicola (Oo). The disease is characterized by skin lesions that can range from mild to severe with associated fatalities documented. Subclinical infections have also been described presenting a wide variability of the impact Oo has on the host. In wild snakes, infections have most often been documented in North America, but increasing numbers of reports are becoming available from other parts of the world, including Europe. While monitoring dice snake (Natrix tessellata) populations in 2018 at Schleuse Hollerich/Lahn, a nature reserve in Germany, three dice snakes were observed with cutaneous granulomas. One year later, snakes with granulomas were also observed, and two dice snakes were captured and examined. Fungal hyphae were found in skin biopsies of the lesions and Oo was detected by PCR in the shed skin from one of the snakes. After shedding, the snakes appeared clinically healthy and were released back to the location at which they had been found. This is the first report of histologically confirmed ophidiomycosis in dice snakes and the first confirmed report of ophidiomycosis in a wild snake in Germany.