Fenbendazole (Panacur: Hoechst) has a low degree of toxicity, teratogenicity and adverse effects on the reproductive tract, and a high degree of safety in experimental animals. Acute, subacute and long-term toxicity trials in cattle given fenbendazole at dosages of up to 2 g/kg revealed no adverse effects. Studies of teratogenicity, effects on fertility, compatibility with other drugs, and safety for animal handlers had similarly negative results.