Anthelmintic efficacy of fenbendazole and levamisole in native fowl in northern Iran.

Our results indicated that fenbendazole and levamisole effectively reduced the number of nemathodes in three Iranian domestic chicken flocks. Given the results of our study, resistance can be expected in the parasitic helminths of poultry. Additional larger scale studies are required to determine the prevalence of anthelmintic resistance in the poultry industry.