The aim of this study was to compare the pharmacokinetics of ivermectin and its antiparasitic activity in two horse breeds. Eight Hutsul and 14 Toric horses were administered ivermectin orally at a dose of 0.2 mg/kg body weight. Blood samples were collected for 96 hr, and faecal samples were collected one day before and on days 14 and 21 after drug administration. Ivermectin concentrations in plasma samples were determined by high‐performance liquid chromatography. Ivermectin concentration was significantly higher in Toric than in Hutsul horses 90 min after ivermectin administration and was maintained at higher level for up to 96 hr. The area under the concentration versus the time curve from 0 to the last sampling point (AUC_0→t) and the maximum plasma concentration (C_max) were significantly higher in Toric than in Hutsul horses (1792.09 ± 246.22 μg × hr/L vs. 716.99 ± 255.81 μg × hr/L and 62.72 ± 17.97 ng/ml vs. 35.34 ± 13.61 ng/ml, respectively). No parasitic eggs were found in the faecal samples collected from both groups of horses on days 14 and 21 after drug administration. The obtained results indicate that although the pharmacokinetics of ivermectin may differ significantly between horse breeds, these differences do not affect the effectiveness of therapy.

中文翻译：

---

伊维菌素在 Hutsul 和 Toric 马中的药代动力学和抗寄生虫活性

本研究的目的是比较伊维菌素的药代动力学及其在两个马品种中的抗寄生虫活性。八匹 Hutsul 和 14 匹环面马以 0.2 毫克/公斤体重的剂量口服伊维菌素。收集血液样品 96 小时，并在给药前一天和给药后第 14 天和 21 天收集粪便样品。血浆样品中的伊维菌素浓度通过高效液相色谱法测定。施用伊维菌素后 90 分钟，Toric 中的伊维菌素浓度显着高于 Hutsul 马，并保持在较高水平长达 96 小时。从 0 到最后一个采样点 (AUC _0→t ) 和最大血浆浓度 ( C _max) 的 Toric 显着高于 Hutsul 马（分别为 1792.09 ± 246.22 μg × hr/L 对 716.99 ± 255.81 μg × hr/L 和 62.72 ± 17.97 ng/ml 对 35.34 ± 13.61 ng/ml）。给药后第14天和第21天，两组马的粪便样本中均未发现寄生虫卵。获得的结果表明，虽然伊维菌素的药代动力学可能在马品种之间存在显着差异，但这些差异并不影响治疗的有效性。