Efficacy of albendazole against gastrointestinal nematodes of cattle.

Forty-five calves with artificial and pasture-acquired nematode infections were medicated with albendazole at dose levels of 0, 2.5, 5.0, or 10 mg/kg of body weight. A dose level of 2.5 mg/kg removed at least 99% of adult Trichostrongylus axei, Trichostrongylus colubriformis, Cooperia oncophora, and Bunostomum phlebotomum. Burdens of Haemonchus contortus, Strongyloides papillosus, and Ostertagia ostertagi were reduced 79, 88, and 97%, respectively. At a dose level of 5.0 mg/kg, at least 95% of all adult nematodes were removed; at 10 mg/kg, at least 97% were removed. At least 99% of 4th-stage larvae of O ostertagi, T axei, C oncophora and T colubriformis and 96% of H contortus were expelled at a dose level of 2.5 mg/kg. At 5.0 and 10 mg/kg, 99 to 100% of all species of larvae were removed. Trichuris spp adults were slightly susceptible at all dose levels; larvae were susceptible (83%) only at 10 mg/kg.