The Vector-Borne Zoonotic Nematode Thelazia callipaeda in the Eastern Part of Europe, with a Clinical Case Report in a Dog in Poland

Thelazia callipaeda is a zoonotic nematode transmitted by drosophilid flies. It causes ocular thelaziosis, a disease of carnivores, such as dogs, cats, and foxes, and also humans. The parasite has thus far been observed in various areas of Eurasia, including 20 countries within Europe. The present study documents its presence in the south-east region of Poland, near the Ukraine border. An adult nematode was removed from the conjunctival sac of a dog showing ocular inflammation and purulent discharge. The dog’s precise origin is unknown. Based on its localization and morphometrical features, the nematode was identified as a Thelazia callipaeda adult male. The present study is the first report of T. callipaeda in a dog in Poland.