The efficacy of closantel and rafoxanide against fenbendazole- and levamisole-resistant Haemonchus contortus in small ruminants.

摘要

24 sheep and 24 goats of mixed breed and between 9- to 12-months-old, were infected with 5000 third stage larvae of H. contortus strains which were resistant to fenbendazole (FBZ) or levamisole (LEV), respectively. Three weeks later, the animals were divided in 4 groups of 6. The sheep were treated with FBZ at 5 mg/kg body weight, closantel (CLO) at 5 mg/kg or rafoxanide (RAF) at 7.5 mg/kg. The goats were treated with LEV at 15 mg/kg, CLO at 5 mg/kg or RAF at 7.5 mg/kg. The sheep and goats of group4 were untreated controls. All the animals were killed 10 days after treatment and faecal egg count and worm count were determined. CLO and RAF showed 100% efficacy against H. contortus in both the sheep and the goats. Faecal egg count reduction in theFBZ-treated sheep was 46.9% and worm reduction was 51.8%. Faecal egg count reduction in the LEV-treated goats was 75.6% and worm reduction was 66.9%.