Epidemiology of Gastrointestinal Nematodes in Extensively Managed Pastoral Small Ruminants: The Case of Nyangatom District, South Omo Zone, Southern Ethiopia.

Abstract

Gastrointestinal nematode infections pose a significant challenge to the productivity and reproductive performance of small ruminants in Ethiopia. This study is aimed at determining the prevalence of gastrointestinal nematode parasites in small ruminants in one of the pastoral areas of Ethiopia, identifying the main gastrointestinal tract (GIT) parasites, and assessing potential risk factors linked to their occurrence. A cross-sectional study was conducted from June to November 2025 to determine the prevalence of gastrointestinal nematodes in sheep and goats in Nyangatom District, Southern Ethiopia, using both qualitative and quantitative coprological examinations. A total of 384 small ruminants, 176 sheep and 208 goats, were systematically selected from the study population and examined for GIT nematode infection. Of these, 253 (65.89%) tested positive for one or more GIT nematodes. The prevalence was 71.59% in sheep and 61.06% in goats. Among the samples, 198 (51.56%) were positive for strongyle eggs, 15 (3.91%) for Strongyloides eggs, 9 (2.34%) for Trichuris spp. eggs, and 31 (8.07%) for mixed infections. Three risk factors, namely study kebeles, species, and body condition score (BCS), were statistically linked to GIT nematode prevalence. These results highlight the significant impact of gastrointestinal nematode infections on small ruminant health and productivity in the study area. The high prevalence rates call for urgent implementation of effective control measures. Strategic deworming programs should be adopted to reduce infection burdens, and animal health extension workers need to actively educate local communities about parasite control. Overall, this study emphasizes the necessity of integrated parasite management strategies to reduce the negative effects of gastrointestinal nematodes.