Prullage Joseph, Dumont Pascal, Nair Arathy, Liu Manyun, DiCosty Utami, Süssenberger Ricarda
Boehringer Ingelheim Animal Health, Missouri Research Center, 6498 Jade Rd., Fulton, MO, 65251, USA.
Boehringer Ingelheim Animal Health, Georgia Research Center, 3239 Satellite Boulevard, Duluth, GA, 30096, USA.
Parasit Vectors. 2025 Apr 21;18(1):147. doi: 10.1186/s13071-025-06753-8.
Two studies were conducted to determine whether treatment with NexGard Plus (NP), a combination of afoxolaner, moxidectin, and pyrantel, prevents transmission of Borrelia burgdorferi to dogs by naturally infected Ixodes scapularis.
For each study, 20 dogs were randomly assigned to two groups (n = 10/group): NP and negative control. Twenty-eight days post-treatment, each dog was infested with approximately 50 I. scapularis that had a 60% B. burgdorferi infection rate in study 1 and a 38.5% infection rate in study 2. Five days post-infestation, ticks were counted and removed. The B. burgdorferi-specific C6 antibody was tested for using the SNAP 4Dx test (IDEXX) and the Lyme Quant C6 test with serum collected before treatment and infestation and 21, 35, 49, 63, and 75 days post-infestation. Skin biopsies were collected 76 days post-infestation and quantitative polymerase chain reaction (qPCR) conducted to detect B. burgdorferi DNA.
On the day of count and removal, no ticks were found on treated dogs, while control dogs had an average of 25.1 ticks in study 1 and 19.6 ticks in study 2, for efficacy of 100% (P ≤ 0.0001). All dogs were seronegative before infestation. The first dog in the control groups became seropositive 21 days post-infestation in study 1 and 35 days post-infestation in study 2 by the SNAP 4Dx test and by 21 days post-infestation by the Lyme Quant C6 test in both studies. Ten of 10 dogs in the control group in both studies seroconverted by the end of the study. None of the skin biopsies from treated dogs were positive for B. burgdorferi DNA, while at least three of the four skin biopsies from each of the control dogs tested positive at the end of the studies. No clinical signs of Lyme disease were detected in any of the dogs.
The results of these studies indicate that NexGard Plus administered at a dose close to the minimum recommended dose of 2.5 mg/kg afoxolaner is effective 28 days after a single treatment in the prevention of B. burgdorferi transmission from naturally infected I. scapularis ticks to dogs.
开展了两项研究，以确定由阿福拉纳、莫昔克丁和噻嘧啶组成的复合制剂尼可信 Plus（NP）能否预防莱姆病螺旋体通过自然感染的肩突硬蜱传播给犬类。
每项研究中，20只犬被随机分为两组（每组n = 10只）：NP组和阴性对照组。治疗28天后，每只犬感染约50只肩突硬蜱，在研究1中这些蜱的莱姆病螺旋体感染率为60%，在研究2中为38.5%。感染后5天，对蜱进行计数并移除。使用SNAP 4Dx检测（IDEXX公司）和莱姆定量C6检测，对治疗前、感染前以及感染后21、35、49、63和75天采集的血清检测莱姆病螺旋体特异性C6抗体。感染后76天采集皮肤活检样本，进行定量聚合酶链反应（qPCR）以检测莱姆病螺旋体DNA。
在计数和移除蜱的当天，治疗组犬身上未发现蜱，而对照组犬在研究1中平均有25.1只蜱，在研究2中平均有19.6只蜱，防治效果为100%（P≤0.0001）。所有犬在感染前血清学均为阴性。在研究1中，对照组的第一只犬在感染后21天通过SNAP 4Dx检测血清学转为阳性，在研究2中在感染后35天转为阳性；在两项研究中，通过莱姆定量C6检测，在感染后21天转为阳性。两项研究中对照组的10只犬在研究结束时均发生血清转化。治疗组犬的皮肤活检样本中莱姆病螺旋体DNA均为阴性，而在研究结束时，对照组每只犬的4份皮肤活检样本中至少有3份检测为阳性。所有犬均未检测到莱姆病的临床症状。
这些研究结果表明，以接近2.5mg/kg阿福拉纳最低推荐剂量给药的尼可信Plus，单次治疗28天后可有效预防莱姆病螺旋体从自然感染的肩突硬蜱传播给犬类。
