Cyathostomins (Nematoda, Strongyloidea) are one of the commonest parasites which infect wild and domesticated equids throughout the world. Because of frequent reports on resistance against anthelmintic drugs, herbal preparations are suggested. In this work, we investigated the nematicidal effects of Nicotiana tabacum (Tobacco) and Zataria multiflora extracts on equine Cyathostomin larvae. First, faecal samples identified as positive for small strongyles eggs were cultured and the infective larvae were recovered. Then, the larvicidal effects of different extracts at different concentrations (12.5, 25, 50, 75 and 100 mg/ml) were evaluated at 10, 20, 30, 40 and 50 minutes after exposure. The results demonstrated that all the concentrations of N. tabacum and Z. multiflora extracts had remarkable effects on the viability of larvae from the beginning toward the end of the experiment. The present results suggest that N. tabacum and Z. multiflora could be useful in control strategies against cyathostomine infections in equids, however, in vivo evaluations are still necessary.
