In present study two organized and six unorganized farms of sheep from three agro-climatic zones of Haryana were surveyed to assess the prevalence of anthelmintic resistance in gastrointestinal nematodes to fenbendazole (@ 5 mg/kg b.wt. orally), closantel (@ 10 mg/kg b.wt. orally) and ivermectin (0.2 mg/kg, subcutaneous injection) by faecal egg count reduction test (FECRT). Per cent reduction in faecal egg counts by fenbendazole (FBZ), closantel (CLS) and ivermectin (IVM) in organized  arms ranged from 53.24-60.60% (FBZ), 74.24-76.62% (CLS) and 63.63-69.69% (IVM) while unorganized farms 59.62- 75.56% (FBZ), 79.19-92.47% (CLS) and 69.94-82.79% (IVM). Over all per cent reduction in faecal egg counts in organized and unorganized farms ranged 53.24-75.56% (FBZ), 74.24-92.47% (CLS) and 63.63-82.79% (IVM), respectively. In all cases of anthelmintic resistance, Haemonchus contortus was the predominant parasite involved. Reduction in faecal egg counts indicate multidrug severe to moderate resistance in sheep farms of different agro-climatic zones of Haryana.

Highlights

• H. contortus resistant to anthelmintics.
• Fenbendazole showed severe to moderate resistance, while Closantel & Ivermectin showed moderate resistance.