Background: More than 60 zoonotic diseases can be transmitted from dogs (Canis lupus familiar’s) to humans, one of which is cystic echinococcosis (CE). Approximately 270 million people in Central Asia live in areas at risk for CE, and Mongolia is included in this region. The transmission of zoonotic infection is facilitated by the movement of humans, livestock, and dogs, as well as trade and cross-border interactions between countries. Aim: To determine the helminth fauna in the dog populations of selected soums of Bayan-Ulgii Province, identify zoonotic pathogens, and investigate Taeniidae infection. Materials and Methods: Seven soums of Bayan-Ulgii province bordering the Russian Federation and the People’s Republic of China were selected using a targeted sampling approach. Domestic dogs belonging to 300 individuals who underwent abdominal ultrasound screening for cystic echinococcosis were included after obtaining consent for deworming. Anthelmintic treatment (5 mg/kg) was administered, and fecal samples from 95 dogs were collected post-treatment. Helminth eggs were identified to determine the helminth fauna. DNA was extracted from samples positive for Taeniidae eggs using a DNA extraction kit (Qiagen, Stool DNA kit, Germany). The mitochondrial cox1 gene was amplified by PCR using F/COI and R/COI primers to determine infection status. Results: The helminth fauna of the dog population in Bayan-Ulgii province consisted of members of the Taeniidae family and the genus Ascaris, as well as Toxocara canis, Trichuris vulpis, Macracanthorhynchus catulinus, Oncicola canis, Strongyloides canis, and Alaria canis. Prevalence rates were as follows Taeniidae 10.5%, T. canis 4.2%, S. canis 3.2%, A. canis 2.1%, Ascaris 2.1%, T. vulpis 2.1%, O.canis 3.2%, M. catulinus 5.2%. Among these, T. canis, T. vulpis, A. canis, and members of the Taeniidae family are zoonotic parasites transmissible from dogs to humans. DNA was extracted from 10 samples positive for Taeniidae eggs. Amplification of the cox1 gene using COI primers revealed an 880 bp band in 9 samples (90%), confirming infection. Conclusions 1. The helminth fauna of dogs in selected soums of Bayan-Ulgii Province consisted of helminths belonging to 1 family, 1 genus, and 6 species. 2. Taeniidae infection was detected in 9.0% of dogs in the selected soums of Bayan-Ulgii Province.

Background: The family Taeniidae (Ludwig, 1886) belongs to the class Cestoda, phylum Platyhelminthes, and order Cyclophyllidea. Zoonotic parasites within this family, particularly Taenia and Echinococcus species, impose a significant socio-economic burden in developing countries. Aim: To determine the prevalence of Taeniidae infection in the domestic dog population of selected soums in Sukhbaatar Province and to identify associated risk factors. Materials and Methods: A total of 135 domestic dogs from seven soums bordering China in Sukhbaatar Province were dewormed, and post-treatment fecal samples were collected for the detection of Taeniidae eggs. DNA was extracted from egg-positive samples using the QIAamp Fast DNA Stool Mini Kit (QIAGEN, Germany). The cox1 gene was amplified using F/COI and R/COI primers through polymerase chain reaction (PCR) to confirm infection. Associations between Taeniidae infection and potential risk factors were analyzed using univariate and multivariate logistic regression analyses. Results: Taeniidae eggs were detected in 35 of 135 fecal samples (25.9%). The mean number of eggs per gram of feces varied among samples. PCR amplification confirmed Taeniidae infection in 30 of the 35 egg-positive samples (85.7%), producing an 880-base pair fragment. The analysis revealed that several owner-related and management-related factors were significantly associated with an increased risk of Taeniidae infection in domestic dogs, including type of residence (OR=12.18; 95% CI: 1.51-98.89; p<0.019), allowing dogs to roam freely (OR=8.08; 95% CI: 2.19–29.73; p<0.002), and feeding dogs raw livestock viscera (OR=265.12; 95% CI: 16.2-4561.7; p<0.0001). Conclusion A 22.2% prevalence of Taeniidae infection was identified among domestic dogs in selected soums of Sukhbaatar Province. Household living conditions, allowing dogs to roam freely without restraint, and feeding dogs raw livestock organs and offal were identified as significant risk factors associated with Taeniidae infection.