Efficacy of febantel in sheep experimentally infected with five species of gastrointestinal nematodes.

The anthelmintic activity of the guanidine derivative febantel was tested in a total of 76 experimentally infected lambs in two control tests. Doses of 5.0 and 7.5 mg per kg body-weight were administered orally against fourth and pre-adult fifth or adult stages of Haemonchus contortus, Ostertagia circumcincta, Trichostrongylus colubriformis, B unostomum trigonocephalum and Oesophagostomum columbianum. The efficacy was between 98.5 and 100 per cent. The drug was well tolerated.