Background: Gastrointestinal parasites are one of the globally occurring most important diseases that include the groups of cestodes, trematodes, the coccidian and gastrointestinal nematodes, particularly the strongyles are the most pathogenic parasites and limit the production of sheep, goats, cattle, equine.
Methods: Across sectional study was carried out in West Shewa zone of the Oromia regional state from August 2019 to November 2021. Flotation and McMaster techniques were used to recover and quantify Nematode, Monezia eggs and Eimeria oocysts from 659 rectally collected faeces. The parasite causing the infection was identified by the floating method, and the infection intensity was calculated by the modified McMaster method. The severity of infection was classified as mild (50-799 EPG), moderate (800-1200 EPG), or severe (>1200 EPG). Coproculture was conducted to identify strongyle species.
Results and discussion: Out of 659 overall prevalence of gastrointestinal parasites in sheep was 546 (82.7%) (95% CI=79.8-85.6). Among the gastrointestinal parasites genera found in the study, Strongyle spp. 354 (53.72%), Eimeria sp. 375(56.90%), Monezia 120 (18.21%), Strongyloides sp. 113 (17.15%) and Trichuris spp. 76 (11.53%) were identified. The EPG/OPG count showed 2080.96, 1424.78, 240.64, 107.91 and 17.45 burdens of Eimeria, Strongyle spp., Monezia, Strongyloides and Trichuris spp. respectively in decreasing order. Among the positive fecal samples, 204 (30.96%) had single infection and while 342(51.89%) samples had mixed infections. Among sheep population (28.07%) had showed a light infection, followed by (21.85%) heavy infection and (6.98%) moderate infection intensity with gastrointestinal nematodes. The most frequently occurring nematodes were Trichostrongylus spp. (33.4%), followed by Haemonchus spp. 581 (30.7%), Bunosstomum spp. 387 (20.5%), Osephagostomum spp. 158 (8.4%) and Teladorsagia 84 (4.4%), whereas, Chabertia spp. 49 (2.6%) was the least identified gastrointestinal nematode. Among the potential risk factors considered in the study, body condition, season, age and sex were associated with the occurrence of Nematode species; season, age, study areas and body condition with the occurrence of Eimeria species whereas only body condition and agro ecology were associated with the occurrence of Monezia infections (p<0.05). In general, the occurrences of high prevalence of gastrointestinal parasites in the study area suggest that they are major constraints for production and productivity of sheep.
Conclusion: The present study indicated that gastrointestinal parasitic strangle nematodes, Monezia and Eimeria are highly prevalent in sheep in the study areas. This study identified that season, study area, age and body condition of the sheep as risk factors for GIT parasites in sheep were significantly associated with the prevalence of git strongyle nematode, Eimeria and Monezia species infections of sheep.