Shoop W L, Egerton J R, Eary C H, Haines H W, Michael B F, Mrozik H, Eskola P, Fisher M H, Slayton L, Ostlind D A, Skelly B J, Fulton R K, Barth D, Costa S, Gregory L M, Campbell W C, Seward R L, Turner M J
Merck Research Laboratories, Rahway, NJ 07065-0900, USA.
Int J Parasitol. 1996 Nov;26(11):1237-42. doi: 10.1016/s0020-7519(96)00123-3.
Eprinomectin (MK-397 or 4"-epi-acetylamino-4"-deoxy-avermectin B1) is a novel avermectin selected for development as a topical endectocide for all cattle, including lactating dairy cows. Herein, we show its anthelmintic, insecticidal and miticidal activity. To determine its anthelmintic capabilities, eprinomectin was tested topically on Jersey calves at 0.08, 0.2, or 0.5 mg kg-1 in a probe formulation against experimental infections of adult Haemonchus placei, ostertagia ostertagi, Trichostrongylus axei, T. colubriformis, Cooperia oncophora, C. punctata, Nematodirus helvetianus, Oesophagostomum radiatum and Dictyocaulus viviparus. Eprinomectin removed > or = 99% and > or = 98% of the adult stage of every species at the 0.5 and 0.2 mg kg-1 dosage levels, respectively. The lowest dosage (0.08 mg kg-1) produced maximal or near maximal efficacy against most of the adult endoparasites with the exception of T. colubriformis (87%) and C. oncophora (88%). In a separate test, eprinomectin was evaluated topically against the immature stages of species at the same dosages. Results showed > or = 99% and > or = 98% removal of the immature stages of each species at the 0.5 and 0.2 mg kg-1 dosage levels, respectively. The 0.08 mg kg-1 dosage maintained > or = 97% efficacy against 6 species with reduced activity against H. placei (42%) and N. helvetianus (66%). For ectoparasites, eprinomectin was tested topically at 0.16, 0.24, 0.32 or 0.5 mg kg-1 on mixed breed cattle naturally infested with the sucking louse, Linognathus vituli. Complete elimination of lice at all dosages was observed by day 14. Topical delivery of eprinomectin at 0.16, 0.24, 0.32 or 0.5 mg kg-1 to Holstein calves experimentally challenged with horn fly, Haematobia irritans, produced 100% efficacy to challenge by week 2 post-treatment in all dosages groups and 94% and 99% efficacy to challenge at the 0.32 and 0.5 mg kg-1 dosage groups, respectively, at week 4. Topical delivery of eprinomectin at 0.16, 0.24 or 0.5 mg kg-1 to Deutsches Fleckvieh cattle infested with mange mites, Chorioptes bovis, produced > or = 95% control at all dosages levels by day 14 post-treatment and was maintained at or near this efficacious level for the 6-week duration of the trial. No adverse reaction was observed in any animal in any of these tests. In summary, these experimental data indicate that eprinomectin is an excellent broad-spectrum endectocide for cattle and is suitable for topical delivery.
埃普利诺菌素（MK - 397或4''-表 - 乙酰氨基 - 4''-脱氧阿维菌素B1）是一种新型阿维菌素，被选用于开发作为所有牛（包括泌乳期奶牛）的局部用体内外寄生虫驱杀剂。在此，我们展示了其驱虫、杀虫和杀螨活性。为确定其驱虫能力，将埃普利诺菌素以0.08、0.2或0.5毫克/千克的剂量，制成探针制剂局部施用于泽西犊牛，以对抗成年的巴贝斯焦虫、奥斯特他线虫、艾氏毛圆线虫、蛇形毛圆线虫、牛库珀线虫、点状库珀线虫、瑞士细颈线虫、辐射食道口线虫和胎生网尾线虫的实验性感染。在0.5毫克/千克和0.2毫克/千克的剂量水平下，埃普利诺菌素分别清除了每种线虫成虫阶段的≥99%和≥98%。最低剂量（0.08毫克/千克）对大多数成年体内寄生虫产生了最大或接近最大的效力，但蛇形毛圆线虫（87%）和牛库珀线虫（88%）除外。在另一项试验中，以相同剂量对埃普利诺菌素进行局部施用来评估其对各线虫未成熟阶段的效果。结果显示，在0.5毫克/千克和0.2毫克/千克的剂量水平下，分别清除了每种线虫未成熟阶段的≥99%和≥98%。0.08毫克/千克的剂量对6种线虫保持了≥97%的效力，但对巴贝斯焦虫（42%）和瑞士细颈线虫（66%）的活性有所降低。对于体外寄生虫，在自然感染吸血虱（牛血虱）的杂交牛身上，以0.16、0.24、0.32或0.5毫克/千克的剂量局部施用埃普利诺菌素。到第14天观察到所有剂量下的虱子均被完全清除。以0.16、0.24、0.32或0.5毫克/千克的剂量对实验性感染角蝇（血蝇）的荷斯坦犊牛局部施用埃普利诺菌素，在所有剂量组中，到治疗后第2周对攻击的效力为100%，在第4周时，0.32毫克/千克和0.5毫克/千克剂量组对攻击的效力分别为94%和99%。以0.16、0.24或0.5毫克/千克的剂量对感染疥螨（牛蠕形螨）的德国黄牛局部施用埃普利诺菌素，到治疗后第14天，所有剂量水平均产生了≥95%的防治效果，并在为期6周的试验期间维持在或接近这一有效水平。在这些试验中的任何动物身上均未观察到不良反应。总之，这些实验数据表明，埃普利诺菌素是一种出色的牛用广谱体内外寄生虫驱杀剂，适合局部施用。
