Anthelmintic efficacy of Fenbendazole and Levamisole in native fowl in northern Iran

Abstract

Background: With the increasing number of free-range domestic chickens, helminth parasites have potentially become more of a threat in commercial flocks in recent years, and routine poultry deworming is needed to improve efficiency of chicken products. The present study deals with a field trial to study the efficiency of two generally used anthelmintics, Fenbendazole and Levamisole, against gastrointestinal nematodes of domestic chickens in north of Iran. Methods: Out of 45 domestic chicken flocks involved in the study, 20 flocks were selected to participate in fecal egg count reduction testing based on flock size from April 2017 to September 2018. The infected chickens were randomly divided into three equal groups of 30 each. Ninety chickens in the infected groups received one of the following treatments (d 0 of treatment): Group 1: 5 mg kg−1 body weight (BW) Fenbendazole for three consecutive days, Group 2: 16 mg kg−1 BW Levamisole, and Group 3 control: placebo; water + DMSO [1]. The efficiency of the treatments were evaluated by comparing fecal egg count in the treated and control groups.Results: Examination of 3 herds of chicken from the control group showed that 95.0% of the animals were infected with gastrointestinal nematodes with an average geometric value of 361 eggs per gram of feces. Fenbendazole at a dose of 5 mg kg−1 BW for three days showed an efficiency of 83.7% (P ≥0.05), and Levamisole at a dose of 16 mg kg−1 BW showed 71.8% (P ≥0.05) with geometric mean eggs in a gram of feces 100 and 199.6, respectively. In general, Fenbendazole and Levamisole showed significantly lower activity. The result of this study revealed that Fenbendazole was a better and effective dewormer than Levamisole on the three Iranian domestic chicken flocks, but it is not significant. Capillaria spp., were the most generally resistant nematodes followed by Trichostrongylus spp., and Amidostomum anseris.Conclusion: Our results indicated that Fenbendazole and Levamisole reduced number of nemathodes effectively in three Iranian domestic chicken flocks. Given the results of our study, it is possible that resistance may be expected in the parasitic helminths of poultry. Additional studies with a larger scale are required to determine the prevalence of anthelmintic resistance in the poultry industry.