Antiparasitic Activity of Ivermectin in Critical Tests in Equids

作者：Ε. T. Lyons, J. Harold Drudge, S. C. Tolliver · 发表于：American Journal of Veterinary Research · 年份：1980 · DOI：10.2460/ajvr.1980.41.12.2069 · 被引用次数：34 · 研究领域：Helminth infection and control

SUMMARY Ten critical tests, using 9 horses and 1 pony, were conducted to evaluate antiparasitic activity of a solution of ivermectin [22, 23-dihydroavermecin B1 (MK-933)] administered in single doses via stomach tube at dosage rates of 50 (3 tests), 100 (3 tests), or 200 (4 tests) μg/kg of body weight. Removal of 91% to 100% was recorded at all 3 dosage levels (No. of infected animals in parentheses) for 2nd instar (7) and 3rd instar (10) Gaserophilus nasalis, immature (5) and mature (5) Oxyuris equi, Strongylus vulgaris (9), S edentatus (8), and small strongyles (10; only 83% removal in 1 animal at 100 μg/kg). Small strongyles in 2 animals were from benzimdazole-resistant sources and removal was 96% (200 μg/kg) and 100% (100 μ/kg). All mature Parascaris equorum parasites in 2 animals (50 μg/kg) and S equinus in 2 animals (100 μg/kg and 200 μg/kg) were removed. Removal of G intestinalis 2nd instar (9) was 79% to 100%, 97% to 99%, and 100%, and of 3rd instar (10) was 67% to 88%, 86% to 100%, and > 99% to 100% at dosage rates of 50, 100, or 200 μg/kg, respectively. Probable activity against 4th-stage Habronema spp, 5th-stage Habronema muscae, or both (all 3 dosage levels) and 5th-stage Draschia megastoma (100 μg/kg) was indicated. There was no activity found against tapeworms (Anoplocephala magna and A perfoliata). Transient loosening of feces was obtserved for 1 animal 200 (μg/kg) after treatment but whether it was drug related was unknown.