Detection of benzimidazole resistance in Haemonchus contortus of sheep in Tamil Nadu, using faecal egg count reduction test

A study was undertaken to determine the resistance against albendazole, fenbendazole, levamisole and closantel in gastro intestinal nematodes of sheep in an organised farm of Tamil Nadu. The resistance was demonstrated by using faecal egg count reduction test (FECRT) in naturally infected sheep. The percentage reduction in egg count for levamisole and closantel was above 95 per cent, while albendazole and fenbendazole was less than 95 per cent and the recovery of third stage larvae of Haemonchus contortus and other post faecal culture confirmed the benzimidazole resistance in H. contortus of sheep.