Coccidiosis in South American camelids: A review of Eimeria species, diagnostic limitations and research gaps.

Protozoan parasites of the genus Eimeria represent important enteric pathogens of South American camelids (SACs), particularly affecting juvenile alpacas and llamas. Despite their veterinary and economic significance, current knowledge regarding camelid coccidiosis remains limited, especially in relation to species taxonomy, endogenous development, molecular diagnostics, and species-specific treatment strategies. This review summarizes current knowledge on Eimeria species infecting SACs, including their morphology, life cycle, epidemiology, pathogenicity, diagnosis, treatment, and prevention. Particular attention is given to the unique biological characteristics of large camelid coccidia such as Eimeria macusaniensis, diagnostic challenges associated with prolonged prepatent periods and intermittent oocyst shedding, and the limited availability of validated molecular diagnostic methods. The review further highlights the lack of approved anticoccidial therapies and the frequent reliance on treatment protocols extrapolated from domestic ruminants. Finally, major research gaps and future perspectives are discussed, emphasizing the need for improved molecular characterization, early diagnostic tools, and evidence-based therapeutic approaches for camelid coccidiosis.