title: Anthelmintic activity of continuous low doses of fenbendazole into the rumen of sheep.
abstract: Fenbendazole (FBZ) was continuously infused for 30 days into the rumen of 103 lambs which had mature or developing benzimidazole-susceptible or thiabendazole-resistant Haemonchus contortus and susceptible Trichostrongylus colubriformis infections. Ovicidal, larvicidal and adulticidal activities were exhibited against benzimidazole-susceptible and benzimidazole-resistant H. contortus worms by FBZ at a dose level of greater than or equal to 0.2 mg kg-1 body weight day-1. Reasonably consistent high level efficacy against H. contortus was obtained with dose levels greater than 0.4 mg kg-1. Excellent control of susceptible T. colubriformis worms was achieved with the lowest dose tested of 0.4 mg kg-1 day-1. The intraruminal infusion critical study method is a tool to determine the feasibility of incorporating a candidate anthelmintic compound in a continuous sustained-release rumen device formulation. The anthelmintic profile of FBZ obtained by low-level intraruminal administration suggests that it would be a potential candidate.
authors.affiliation: Animal Health Discovery Research Department, Eli Lilly and Co., Greenfield, IN 46140.
authors.forename: R J
authors.initials: RJ
authors.lastname: Boisvenue
authors.forename: E L
authors.initials: EL
authors.lastname: Colestock
authors.forename: J C
authors.initials: JC
authors.lastname: Hendrix
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000627:therapeutic use*; D005260:Female; D005273:Fenbendazole / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D006188:Haemonchiasis / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D006189:Haemonchus / Q000187:drug effects* / Q000254:growth & development; D008297:Male; D012417:Rumen / Q000469:parasitology; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy* / Q000469:parasitology; D014251:Trichostrongyloidea / Q000187:drug effects*; D014252:Trichostrongyloidiasis / Q000662:veterinary*; D014253:Trichostrongylosis / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D014254:Trichostrongylus / Q000187:drug effects* / Q000254:growth & development
chemical_list: D001562:Benzimidazoles; D005273:Fenbendazole