title: The effect of single and divided dose administration on the efficacy of fenbendazole against adult stages of benzimidazole resistant sheep trichostrongylids.
abstract: Sheep infected with benzimidazole resistant strains of Haemonchus contortus and Trichostrongylus colubriformis were used to compare the anthelmintic efficacy of fenbendazole given as a single dose or administered in a divided dose regime over five days. Statistical analysis showed no significant difference between the two methods of administration for H contortus. On the other hand, divided dose fenbendazole was significantly less effective than single doses against adult T colubriformis at dose rates of 5 and 7.5 mg/kg. In the case of H contortus a highly significant correlation coefficient between post treatment egg counts and worm counts (r = 0.789) was obtained. This suggests that reduction in faecal egg output following drug treatment would provide a useful field indication of anthelmintic performance of fenbendazole (and possibly related compounds) against benzimidazole resistant strains of this parasite.
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology*; D001562:Benzimidazoles / Q000008:administration & dosage* / Q000494:pharmacology*; D004351:Drug Resistance; D005273:Fenbendazole / Q000008:administration & dosage* / Q000627:therapeutic use; D006188:Haemonchiasis / Q000188:drug therapy / Q000662:veterinary; D006189:Haemonchus / Q000187:drug effects; D008297:Male; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy*; D014251:Trichostrongyloidea / Q000187:drug effects*; D014252:Trichostrongyloidiasis / Q000662:veterinary*; D014253:Trichostrongylosis / Q000188:drug therapy / Q000662:veterinary
chemical_list: D000871:Anthelmintics; D001562:Benzimidazoles; D005273:Fenbendazole