Multiple anthelmintic resistance and the possible contributory factors in Beetal goats in an irrigated area (Pakistan)

This paper presents the first report of multiple anthelmintic resistance in the gastrointestinal nematodes of goats and its possible contributory factors in an irrigated area (Pakistan). A total of 18 privately owned Beetal goat flocks were selected in order to determine the anthelmintic resistance against commonly used anthelmintics. Forty to 48 animals from each flock were selected according to their weight and egg count. The three anthelmintics viz., oxfendazole, levamisole and ivermectin, were given to three groups at manufacturer’s recommended dose while one group was kept as untreated control. Anthelmintic resistance was determined through faecal egg count reduction and egg hatch tests while assessment of the contributory factors of anthelmintic resistance was measured through the rural participatory approach. Faecal egg count reduction test revealed high prevalence of anthelmintic resistance (83.3%) and it was either single (levamisole) or multiple (oxfendazole and levamisole). Egg hatch test confirmed the resistance against oxfendazole as detected with faecal egg count reduction test. None of the goat flocks was resistant to ivermectin. Copro-cultures revealed that Haemonchus contortus, Trichostrongylus colubriformis and Teladorsagia circumcincta were the most common species exhibiting resistance to levamisole and oxfendazole. Step-wise logistic regression of the data on worm control practices revealed significant role of under-dosing, low-protein diets, healthcare supervision by the traditional healers and mass treatments.