Ticks are cosmopolitan vectors of numerous diseases, and detection of various pathogens in ticks can help to assess their distribution. In the current study, 528 adult ticks were collected from grazing animals or the ground in ten different Mongolian provinces. Dermacentor nuttalli constituted 76.1% of them and was found in all ecozones except the eastern desert. Dermacentor marginatus (8.3%), Dermacentor silvarum (1.1%) and Ixodes persulcatus (3.0%) were found in the northern forest areas and Hyalomma asiaticum (11.4%) only in the southern (semi-)desert. Of these, 359 ticks were subjected to DNA extraction and PCR was carried out to detect various pathogens. Anaplasma spp. was found in D. marginatus and D. nuttalli (2.5% positive each), including flagged specimen and identified as Anaplasma phagocytophilum. Borrelia spp. were found in 2.5% of the ticks (mostly in I. persulcatus) and identified as Borrelia garinii. Babesia spp. (40%) identified as Babesia caballi were detected in all five tick species including flagged Dermacentor spp. and I. persulcatus, and 3.5% of the ticks (all species except D. silvarum) were positive for Theileria spp. identified as Theileria equi. The piroplasms were found in all provinces. Tick-borne encephalitis virus was not detected. The results highlight the high risk of equine piroplasmosis in Mongolia, which is a concern for both the nomadic population who rely on horses for transport and for conservation of Przewalski's horses in Mongolia. In addition, zoonotic agents such as the avian B. garinii and A. phagocytophilum were also detected, outlining a high risk for exposed humans.
Keywords: Anaplasmosis; Borreliosis; Horses; Ixodid ticks; Piroplasmosis; TBE.