Fenbendazole is a broad spectrum benzimidazole anthelmintic used against gastrointestinal parasites.Target: AntiparasiticFenbendazole is a broad spectrum benzimidazole anthelmintic used against gastrointestinal parasites including: giardia, roundworms, hookworms, whipworms, the taenia species of tapeworms(It is effective against the Taenia species of tapeworm but not against the common tapeworm, Dipylidium caninum.), pinworms, aelurostrongylus, paragonimiasis, strongyles and strongyloides and can be administered to sheep, cattle, horses, fish, dogs, cats, rabbits and seals. Drug interactions may occur if using bromsalan flukicides such as dibromsalan and tribromsalan. Abortions in cattle and death in sheep have been reported after using these medications together. Fenbendazole is poorly absorbed from the gastrointestinal tract in most species. The LD50 in laboratory animals exceeds 10 g/kg when administered orally. From Wikipedia.

References:
[1]. http://en.wikipedia.org/wiki/Fenbendazole