Insights into Non-Antibiotic Alternative and Emerging Control Strategies for Chicken Coccidiosis

Coccidiosis, caused by an obligate intracellular parasite of the genus Eimeria, is the most economically parasitic disease in poultry. Long-term reliance on synthetic anticoccidials and ionophores has accelerated the emergence of drug resistance and intensified the need for effective, residue-free alternatives. This narrative review synthesizes findings from peer-reviewed studies published between 1998 and 2025, summarizing advances in non-antibiotic control strategies encompassing five domains: (i) phytochemicals and botanicals, (ii) functional nutrition and mineral modulators, (iii) microbial and gut modulators, (iv) host-directed immunological and biotechnological approaches, and (v) precision and omics-guided biotherapeutic platforms. These approaches consistently reduce lesion severity, oocyst shedding, oxidative stress, and mortality while improving growth parameters in a variety of Eimeria models. However, translation to field settings remains constrained by variable bioactive composition, limited standardization, inadequate pharmacokinetic data, and the scarcity of large-scale, multi-farm validation studies. This review provides a concise summary of current evidence and delineates critical knowledge gaps to guide the development, optimization, and deployment of next-generation anticoccidial strategies. Together, natural products and emerging biotechnologies provide a promising foundation for sustainable, high-welfare, antibiotic-independent coccidiosis control.