A Systematic Review and Meta-Analysis of Studies on the Prevalence of Gastrointestinal Parasites Among Ruminants in Nigeria

Gastrointestinal (GI) parasites pose a significant challenge to livestock production, particularly in tropical regions like Nigeria, where conditions favor their transmission. Although numerous studies have investigated GI parasite prevalence in Nigerian ruminants, findings remain inconsistent due to differences in methodology and diagnostics. This systematic review and meta-analysis synthesized data from 42 studies published between 2000 and 2024 to estimate pooled prevalence and explore geographic, host, and sampling site variations. A total of 9,489 infections were reported among 18,208 ruminants, yielding an overall prevalence of 52.1% (95% CI: 0.51–0.52). The pooled prevalence was 57% (95% CI: 0.47–0.66), with substantial heterogeneity (I² = 99%, p < 0.001). Subgroup analysis revealed significant differences by region (χ² = 10.85; p = 0.05), sampling site (χ² = 34.38; p < 0.01), and host species (χ² = 42.16; p < 0.01). The findings confirm widespread GI parasitism in Nigerian ruminants, with marked regional and host-specific variability. This study provides critical insight into the distribution of GI parasites and highlights areas where targeted control measures are most needed.