Department of Equine, Small Animal, Poultry and Wild Animal Diseases, Faculty of Veterinary Medicine, University of Belgrade, Bul. oslobodjenja 18, 11000, Belgrade, Serbia.
Department of Biology, Faculty of Veterinary Medicine, University of Belgrade, Bul. oslobodjenja 18, 11000, Belgrade, Serbia.
Parasit Vectors. 2019 May 28;12(1):270. doi: 10.1186/s13071-019-3521-9.
Canine generalized demodicosis is a common parasitic disease caused by the proliferation of Demodex mites. The introduction of isoxazoline class treatments in veterinary dermatology has resulted in apparently effective treatment of generalized demodicosis. The objective of this study was to evaluate the effectiveness of fluralaner for the treatment of canine generalized demodicosis using real-time PCR for the detection and quantification of Demodex DNA.
Twenty privately owned dogs with clinical symptoms of generalized demodicosis and deep skin scrapings positive for Demodex canis mites were enrolled in the study. Following diagnosis (day 0) each dog was treated with fluralaner at the recommended commercial dose for tick and flea treatment (25-56 mg/kg) based on body weight. Clinical and mite count assessments, and hair sampling for molecular analyses were performed on days 0, 28, 56, 84 and 112. Demodex DNA was detected and quantified using real-time PCR.
A single oral dose of fluralaner reduced Demodex mite counts in skin scrapings by an average of 98.9% in all dogs by day 28. No mites were recovered from skin scrapings from any treated dog by day 56, at which time the dog was considered to be clinically cured, with total hair regrowth. There were significant differences among examined dogs in qPCR cycle threshold (Ct) values on days 0, 28, 56, 84 and 112. Demodex DNA levels decreased (increasing Ct values) throughout the study. Mite DNA was present on day 112, possibly from dead mites, at values significantly lower than in samples taken on days 0, 28 and 56. Based on qPCR testing of diluted samples, the Demodex mite population was reduced by approximately 1000-fold on day 112.
Oral administration of fluralaner at the recommended dose to dogs with generalized demodicosis is highly effective for reducing Demodex mite populations and resolving clinical signs of generalized demodicosis. The presence of mite DNA may indicate that treatment did not kill all Demodex mites.
犬类全身性蠕形螨病是一种常见的寄生虫病，由蠕形螨过度繁殖引起。伊维菌素类药物在兽医皮肤科的应用，使全身性蠕形螨病的治疗效果明显。本研究旨在通过实时 PCR 检测和定量犬蠕形螨 DNA，评估氟雷拉纳治疗犬类全身性蠕形螨病的疗效。
20 只患有全身性蠕形螨病且皮肤深刮物中检出犬蠕形螨的私人拥有犬被纳入研究。确诊后（第 0 天），每只犬根据体重以推荐的用于蜱和跳蚤治疗的商业剂量（25-56mg/kg）口服氟雷拉纳。在第 0、28、56、84 和 112 天进行临床和螨虫计数评估以及毛发采样进行分子分析。使用实时 PCR 检测和定量蠕形螨 DNA。
所有犬在第 28 天单次口服氟雷拉纳后，蠕形螨数量平均减少 98.9%。在第 56 天，没有从任何治疗犬的皮肤刮片中回收螨虫，此时犬被认为临床治愈，毛发完全再生。在第 0、28、56、84 和 112 天，检查犬的 qPCR 循环阈值（Ct）值存在显著差异。整个研究过程中，蠕形螨 DNA 水平下降（Ct 值增加）。在第 112 天，可能是由于螨虫死亡，仍存在螨虫 DNA，但含量明显低于第 0、28 和 56 天的样本。根据对稀释样本的 qPCR 检测，第 112 天蠕形螨种群减少了约 1000 倍。
推荐剂量口服氟雷拉纳治疗犬全身性蠕形螨病，可有效降低蠕形螨数量并缓解全身性蠕形螨病的临床症状。螨虫 DNA 的存在可能表明治疗没有杀死所有的蠕形螨。
