Crossroad between the sylvatic and domestic cycles of Mesocestoides litteratus: mesocestodiasis in dogs adopted from shelters in Türkiye.

This study aimed to report the presence of Mesocestoides litteratus in dogs adopted from shelters in Türkiye. Gravid segments were examined microscopically in the faeces of dogs from different shelters located in Ankara and Kirikkale provinces in the central region of Türkiye. Then, genomic DNA obtained from these segments, a 446-bp fragment of the mitochondrial cytochrome C oxidase subunit 1 gene, and a 350-bp fragment of mitochondrial 12S rRNA were amplified and sequenced. BLASTn search was performed. During light microscopic examination, an egg-filled paruterine organ was observed in the middle part of the segment. Thin-shelled, oval, 35-µm-diameter parasite eggs containing an oncosphere with three pairs of hooklets were observed. The gravid segments were determined as Mesocestoides spp. based on the appearance of the typical paruterine organ. PCR results supported our diagnosis; moreover, according to the BLAST results, it was detected that the species infecting two dogs was 98.01-100% similar to M. litteratus. Praziquantel-containing medication was administered to the infected dogs at a dosage of 5 mg/kg. Foxes act as the final host of M. litteratus and the parasite is prevalent in wildlife; however, these animals may disperse the parasite in urban life. Veterinarians need to be made more aware of this parasite, especially if the dogs are owned from shelters.