Objective: In the spring of 2016 (1395,date of Iran), the use of anti-parasitic drugs sporadically using pills and injections under the skin on the number of lambs in Ilam province. These drugs have therapeutic effect on nematodes of the digestive system. Materials and Methods: In the laboratory, a test based on reducing the number of eggs per gram of stool samples was performed on a flock of sheep. A total of 45 lambs aged were used between 8 to 11 months. Initial testing stool with an average number of eggs per gram was higher than 500. Lambs selectively and sporadically were divided into 5 groups in three different herds. The sheep of the groups 1 to 4 were treated respectively with subcutaneous injection of ivermectin (200 mcg / kg), levamisole (7.5 mg / kg) and mebenbendazole (3.75 mg / kg) and the fourth oral dosage group of Albendazole at 10%, while the group 5 remained as control without treatment. Results & Conclusion: The reduction count of Eggs per gram carried out ten days Later showed a reduction of 92.73% in lambs treated with Ivermectin, 94.84% in treated patients With levamisole, and in those treated with Albendazole and mebendazole reduction was 69.22%. The cultivation of larvae Performed later showed growth of Haemonchus sp. in the Feces of the treated lambs. This is means that Haemonchus sp. Parasitic sheep Resistant to antiparasitics drugs.
