Critical tests of anthelmintic activity of a paste formulation of thiabendazole in horses

Critical tests of the activity on large strongyles, ascarids, mature pinworms, and bots were carried out in 11 horses intraorally treated with a paste formulation of thiabendazole. The dose level of 44 mg/kg was administered to 3 horses, and the dose level of 88 mg/kg to 8 horses. Removals of Strongylus vulgaris and mature Oxyuris equi were 100% at the 2 dose levels, and efficacy against Strongylus edentatus varied from 95 to 99% and 89 to 100% for the 44- and the 88-mg/kg dose levels, respectively. Strongylus equinus was completely removed from the 1 infected horse treated at the dose level of 88 mg/kg. Activity of the smaller dose against Parascaris equorum was 46%, and that of the larger dose varied from 32 to 100%. The drug was inactive on Gasterophilus intestinalis and Gasterophilus nasalis.