Detection of anthelmintic resistance using in vitro test procedures

In vitro egg hatch assay and larval paralysis test were performed using thiabendazole, mebendazole and levamisole on Haemonchus contortus isolated from the Central Sheep and Wool Research Institute, Avikanagar to detect anthelmintic resistance. LC50 values for thiabendazole and mebendazole were 0.239±0.012 μg/ml, and 30.48±0.051 μg/ml, respectively, indicating benzimidazole resistance. However, the LC50 value for levamisole on larval paralysis test (LP) was 0.683±0.049 μg/ml. The problems associated with the larval paralysis test have been discussed.