Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 9 2 2014 06 15 169 180 EN Abdul Razzaq Animal Sciences Research Program, Balochistan Agricultural Research and Development Centre, PARC, Brewery Road, Quetta, Pakistan. Kamran Ashraf Dept. of Parasitology, University of Veterinary and Animal Sciences, Lahore, Pakistan. Azhar Maqbool Dept. of Parasitology, University of Veterinary and Animal Sciences, Lahore, Pakistan. Muhammad Islam International Centre for Agriculture Research in Dry Areas (ICARDA), National Agricultural Research Centre, Islamabad, Pakistan. Abdul Hanan Range and Forestry Research Program, Balochistan Agricultural Research and Development Centre, PARC, Brewery Road, Quetta, Pakistan. Mian Muhammad Awais Dept. of Pathobiology, Sub campus Jhang, University of Veterinary and Animal Sciences, Lahore, Pakistan. Munir Ahmad Khetran Crop Sciences Research Program, Balochistan Agricultural Research and Development Centre, PARC, Brewery Road, Quetta, Pakistan. Saadullah Jan Centre for Advance Studies in Vaccinology and Bacteriology, University of Balochistan, Quetta, Pakistan. Muhammad Shafee Centre for Advance Studies in Vaccinology and Bacteriology, University of Balochistan, Quetta, Pakistan. Muhammad Essa Diseases Investigation Lab. Livestock and Dairy Development Department, Quetta, Pakistan. Hamdullah Kakar Dairy Farm, Livestock and Dairy Development Department, Quetta, Pakistan. 2015 10 14   Background:Among the infectious organisms of parasitic origin, gastrointestinal nematodes are very important as they have been reported worldwide. The main aim of the present research study to highlight the annual epidemiological contributing factors associated with the prevalence of gastrointestinal nematodes and their control in sheep. Methods:A total 1200 faecal samples (100 per month) were collected from farmers holding Balochi-sheep (either sexes, 1-5 years old) during January-December 2012 and analyzed to determine the prevalence of nematodes based on microscopy and ELISA based diagnostic assay. Therapeutic efficacies of different synthetic and herbal medicines against these nematodes were assessed by field trials. Results:Results showed that 23.92% Balochi-sheep were infected with nematodes. Five nematodes infections were recorded with highest prevalence of Haemonchus (7.75%) fol-lowed by Nematodirus (7.58%), Strongyloides (4.42%), Trichostrongylus (2.33%) and Trichuris (1.83%). The younger and older ewes (one and five years) presented higher nematodes prevalence with peak during March/April and August/September. Haemonchus and Tri-churis positive samples based on coprological examination were also showed 92-100% positive sensitivity for these nematodes by the ELISA. Sheep treated with Ivermectin showed higher reduction (97.76%) in nematode egg counts followed by Atreefal deedan (96.42%) and Oxfendazole (95.44%), respectively. Conclusion:The gastro-intestinal nematodes are prevalent in all age and either sex of Balochi-sheep with peak during summer. The ELISA based diagnosis is more accurte. The synthetic and herbal products are very effective against sheep nematodes. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/416 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/416/328