Department of Veterinary Medicine, University of Bari, Valenzano, 70010, Italy.
Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran.
Parasit Vectors. 2021 Apr 13;14(1):199. doi: 10.1186/s13071-021-04704-7.
Onchocerca lupi and Cercopithifilaria spp. are vector-borne filarioids of dogs, which harbour skin microfilariae (mfs), the former being of zoonotic concern. Proper treatment studies using compounds with microfilaricidal activity have not been performed. Therefore, this study aimed to assess the efficacy of a commercially available spot-on formulation containing moxidectin 2.5%/imidacloprid 10% for the treatment of O. lupi or Cercopithifilaria spp. skin-dwelling mfs in naturally infected dogs.
Privately owned dogs (n = 393) from southern Portugal were sampled via skin biopsies to identify and count mfs in 20 µl of skin sediment. A total of 22 mfs-positive dogs were allocated to treatment group (n = 11; G1) or left untreated as a control (n = 11; G2). As a pilot investigation to test the treatment efficacy, five dogs assigned to G1 were treated four times at monthly intervals with moxidectin 2.5%/imidacloprid 10% spot-on formulation on SDs 0, 28 (± 2), 56 (± 2), and 84 (± 2). Based on the negative results for both O. lupi and/or Cercopithifilaria spp. mfs of dogs in the pilot study from SD28 onwards, the remaining six dogs in G1 were treated at SD0 and assessed only at SD28.
Of the 393 animals sampled, 78 (19.8%) scored positive for skin-dwelling mfs. At the pilot investigation, a mean number of 19.6 mfs for O. lupi was recorded among five infected dogs whereas no mfs were detected at SD28. At SD0, the mean number of Cercopithifilaria spp. larvae was 12.6 for G1 and 8.7 for G2. The mean number of mfs for G2 was 20.09.
Results herein obtained suggest that a single treatment with moxidectin 2.5%/imidacloprid 10% spot-on formulation is efficacious against skin-dwelling mfs in dogs. The microfilaricidal effect of moxidectin could also be useful in reducing the risk of O. lupi infection for humans.
狐盘尾丝虫和细颈囊尾蚴是犬类的两种经媒介传播的丝虫，它们体内寄生着皮肤微丝蚴（mf），前者具有动物源性传染病的风险。尚未进行使用具有杀微丝蚴活性的化合物的适当治疗研究。因此，本研究旨在评估一种市售的莫昔克丁 2.5%/吡虫啉 10%的滴剂配方对治疗自然感染犬的狐盘尾丝虫或细颈囊尾蚴皮肤寄生 mf 的疗效。
从葡萄牙南部的私人拥有的犬中采集皮肤活检样本，通过 20μl 皮肤沉积物中的微丝蚴计数来识别和计数微丝蚴。共有 22 只 mf 阳性犬被分配到治疗组（n=11；G1）或不治疗作为对照组（n=11；G2）。作为测试治疗效果的试点研究，5 只被分配到 G1 的犬每月用莫昔克丁 2.5%/吡虫啉 10%滴剂治疗 4 次，分别在 SD0、28（±2）、56（±2）和 84（±2）。基于从 SD28 开始 pilot 研究中狗的狐盘尾丝虫和/或细颈囊尾蚴 mf 的阴性结果，G1 中剩余的 6 只犬仅在 SD28 进行治疗。
在所采集的 393 只动物中，78 只（19.8%）的皮肤寄生 mf 呈阳性。在 pilot 研究中，5 只感染犬的狐盘尾丝虫的平均 mf 数量为 19.6，而在 SD28 时未检测到 mf。在 SD0 时，G1 中 Cercopithifilaria spp.幼虫的平均数量为 12.6，G2 为 8.7。G2 的 mf 平均数量为 20.09。
本研究结果表明，单次使用莫昔克丁 2.5%/吡虫啉 10%滴剂治疗对犬的皮肤寄生 mf 有效。莫昔克丁的杀微丝蚴作用也可用于降低人感染狐盘尾丝虫的风险。
