Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 16 2 2021 05 28 318 326 EN Slavica Zivkovic Agricultural School PKB, Pančevački Put 39, Krnjača, Belgrade, Serbia Ivan Pavlovic Scientific Veterinary Institute of Serbia Vojvode Toze 14, Belgrade, Serbia Bojana Mijatovic Agricultural School PKB, Pančevački Put 39, Krnjača, Belgrade, Serbia Ivana Trailovic Faculty of Veterinary Medicine, University of Belgrade, Belgrade, Serbia Dragisa Trailovic Faculty of Veterinary Medicine, University of Belgrade, Belgrade, Serbia 2017 08 09 2021 05 28 Background: This study aimed to investigate the prevalence, intensity and risk factors (age and gender) promoting the intestinal helminthic infections of the Domestic mountain ponies and Balkan donkeys in Serbia. Methods: Prevalence, intensity and risk factors influencing helminth infection in horses (n=39) and donkeys (n=18) at the site of Nature Park Stara Planina, were studied from May to Sep 2015. The presence of one or several gastrointestinal helminth species was confirmed by faecal flotation in 97.43% of horses and 88.88% of donkeys included in the monitoring. The identified helminth species were Trichostrongylus axei, Strongylus edentatus, S. vulgaris, Parascaris equorum, Dictyocaulus arnfieldi and Anoplocephala magna in 84.61%, 46.15%, 5.13%, 58.97%, 94.87% and 38.46% of horses, respectively. The significant association of infection with P. equorum and sex of horses was established. (χ2=13.33, P<0.01). Results: The prevalence of parasitic helminths identified in donkeys was the following: D. arnfieldi, T. axei, Pa. equorum, S. vulgaris, A. margna and Strongyloides westeri in 55.55%, 38.89%, 27.78%, 22.22% and 22.22% of donkeys, respectively. Moreover, the mean faecal egg count was higher in donkeys (369.9 EPG - egg per gram) than in horses (250.2 EPG). The association between the age and the mean EPG was significant (P<0.05) in both equine species. Conclusion: The results of the investigation provided basic information that can be helpful for planning strategic control of nematode infection in equine population in Nature Reserves in Serbia. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/1724 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/1724/1138