New Cases of Thelazia callipaeda Haplotype 1 in Dogs Suggest a Wider Distribution in Romania.

Thelazia callipaeda is an emerging vector-borne zoonotic helminth parasitizing the conjunctival sac of a broad spectrum of definitive hosts, such as dogs, cats, rabbits, wild carnivores, and humans. Its presence is associated with mild to severe ocular disease. Here, we report two new clinical cases in dogs originating from western and southern Romania, with no travel history. On clinical examination, the nematodes were retrieved from the conjunctival sac and identified using morphological keys and molecular tools. Twenty-two adult nematodes (8 males, 14 females) were collected and were identified as T. callipaeda by morphology. The molecular analysis revealed a 100% identity with haplotype h1 of T. callipaeda. This study describes the occurrence of new autochthonous cases of thelaziosis in Romania, reinforcing the spreading trend of this zoonotic eyeworm and highlighting the need for increased awareness among medical and veterinary practitioners. Moreover, we provide additional molecular evidence for the exclusive distribution of haplotype 1 of T. callipaeda in Europe.