A survey of anthelmintic resistance in gastrointestinal nematodes in sheep of Haryana.

Twenty five flocks of sheep (five from each district) from different villages of Fatehabad, Bhiwani, Jind, Rohtak and Sirsa dis tricts of Haryana were surveyed to assess the prevalence of anthelmintic resistance in gastrointestinal nematodes to morantel citrate (10 mg/ kg) and ivermectin (0.2 mg/kg) by faecal egg count reduction test. Per cent reduction in faecal egg counts by morantel and ive rmectin was 93 and 92 in village Badopal (Fatehabad); 93 and 89 in village Badeha (Bhiwani) and 92 and 94 in village Badsi (Bhiwani), r espectively. In these villages, the 95% confidence limit was below 90% indicating slight resistance to morantel citrate and ivermectin. In a ll cases of anthelmintic resistance, Haemonchus contortus was the predominant parasite involved. Reduction in faecal egg counts was 95% in all other 22 village flocks treated with morantel and ivermectin of the above districts indicating no resistance.