title: Field trials with closantel and Haemonchus contortus in sheep in Papua New Guinea.
abstract: Sheep treated once with closantel at 7.5 or 15.0 mg/kg and grazing with untreated sheep remained free of Haemonchus contortus for at least 4 to 5 weeks and 6 to 7 weeks respectively after treatment. When the whole flock was treated with 15.0 mg/kg, H. contortus began to become re-established 7 to 8 weeks later. Maximum benefit of the residual anthelmintic effect of closantel against H.contortus was obtained only when all sheep in the flock were treated; it took 10 weeks longer for H.contortus to form 50% of larval cultures when the whole flock was treated than when only a part of the flock was treated.
authors.affiliation: National Veterinary Laboratory, Department of Agriculture & Livestock, Boroko, Papua New Guinea.
authors.forename: I L
authors.initials: IL
authors.lastname: Owen
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004341:Drug Evaluation; D005260:Female; D006188:Haemonchiasis / Q000188:drug therapy / Q000517:prevention & control / Q000662:veterinary*; D006189:Haemonchus / Q000187:drug effects / Q000502:physiology; D007476:Ionophores / Q000008:administration & dosage / Q000627:therapeutic use*; D007814:Larva / Q000187:drug effects; D008297:Male; D010219:Papua New Guinea; D010270:Parasite Egg Count; D012457:Salicylamides / Q000627:therapeutic use*; D012458:Salicylanilides / Q000008:administration & dosage / Q000627:therapeutic use*; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy* / Q000453:epidemiology; D013997:Time Factors; D014252:Trichostrongyloidiasis / Q000662:veterinary*; D014329:Tropical Climate
chemical_list: D000871:Anthelmintics; D007476:Ionophores; D012457:Salicylamides; D012458:Salicylanilides; C023342:closantel