Ovacidal activity of febantel

Abstract

Febantel [N-2-([2,3-bis-(methoxycarbonyl)-guanidine] 5-(phenylthio)-phenyl)-2-methoxyacetamide] was found to inhibit the embryonic development of Trichuris muds and Haemonchus contortus ova. After oral treatment of T.muris-infected mice with 500 mg/kg febantel, the majority of eggs excreted from 31 hours after treatment did not develop into the larval stage. A more pronounced ovacidal effect was shown for H.contortus after treatment of sheep with low doses of febantel. The embryonic development of eggs had completely stopped from 24 hours after treatment with 2.5 mg/kg febantel. The commercially recommended dose-rate for febantel in sheep is 5 mg/kg.