Efficacy of Medicinal Plants on Gastrointestinal Parasites in Small Ruminants in Africa: A Systematic Review and Meta-Analysis Protocol

Abstract

Gastrointestinal parasitic infections represent a critical challenge to the health and productivity of small ruminants in Africa. The extensive use and misuse of synthetic anthelmintics have accelerated resistance, necessitating sustainable alternatives such as medicinal plants. Despite increasing attention, reported efficacies of these phytotherapeutic interventions remain inconsistent. This study aims to systematically review and quantify the efficacy of medicinal plants used in Africa for controlling gastrointestinal parasites (GIPs) in sheep and goats. Specifically, it seeks to: (i) estimate pooled effect sizes of medicinal plants against GIPs, (ii) identify the most commonly used species and their administration modes, (iii) assess variations in efficacy across plant types, geographic zones, experimental designs, and host species, (iv) evaluate methodological quality and risk of bias of included studies, and (v) identify knowledge gaps and future research priorities. Following PRISMA-P guidelines, this study will perform a systematic search across PubMed, Web of Science, Scopus, ScienceDirect, CAB Abstracts, SpringerLink, Medline, Cochrane, AJOL, and Google Scholar for studies published between 1990 and 2025. Eligible studies will include randomized and non-randomized controlled trials and observational designs assessing the antiparasitic effects of medicinal plants in small ruminants. Data will be synthesized using a random-effects meta-analysis model, and methodological quality will be critically appraised with a standardized tool. This review will generate pooled efficacy estimates, provide evidence-based recommendations, and support the integration of ethnoveterinary medicine into sustainable parasite management strategies in African livestock production.