title: Ivermectin: activity against larval Strongylus vulgaris and adult Trichostrongylus axei in experimental infections in ponies.
abstract: Activity of ivermectin, administered IM at the dosage rate of 200 micrograms/kg of body weight, was evaluated in controlled tests against migrating larvae of Strongylus vulgaris and adult Trichostrongylus axei in experimental infections in 6 ponies raised worm-free. Ponies were given 2,190 or 2,400 infective 3rd-stage larvae of S vulgaris at 7 days before treatment and 22,000 or 22,750 infective 3rd-stage larvae of T axei at 42 or 45 days before treatment. Three ponies were given ivermectin plus vehicle, and 3 ponies were given the vehicle only; the ponies were euthanatized 7 or 9 days after treatment. At necropsy, 4th-stage S vulgaris larvae were not recovered from visceral arteries of the 3 ivermectin plus vehicle-treated ponies, but 21 to 40 larvae were recovered from each of the 3 vehicle-treated ponies. Also at necropsy, adult T axei (140 specimens) were recovered from only 1 ot the 3 ivermectin plus vehicle-treated ponies, but 4,610 to 6,410 specimens were found in each of the 3 vehicle-treated ponies. Toxicosis was not observed after treatment.
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology* / Q000627:therapeutic use; D006734:Horse Diseases / Q000188:drug therapy*; D006736:Horses; D007559:Ivermectin; D007783:Lactones / Q000494:pharmacology* / Q000627:therapeutic use; D013319:Strongyle Infections, Equine / Q000188:drug therapy; D013320:Strongyloidea / Q000187:drug effects*; D014251:Trichostrongyloidea / Q000187:drug effects*; D014253:Trichostrongylosis / Q000188:drug therapy / Q000662:veterinary
chemical_list: D000871:Anthelmintics; D007783:Lactones; D007559:Ivermectin