MSD Animal Health Innovation GmbH, Zur Propstei, 55270, Schwabenheim, Germany.
Kapriol Bt., Sümeg, 8330, Hungary.
Parasit Vectors. 2023 Jul 27;16(1):252. doi: 10.1186/s13071-023-05820-2.
The isoxazoline fluralaner is effective for prevention of Babesia canis transmission from infected Dermacentor reticulatus ticks to dogs for 84 days in a controlled environment. This study was designed to evaluate the effectiveness of fluralaner chewable tablets for sustained prevention of B. canis infection of dogs in endemic areas under natural conditions.
In Europe, privately owned, clinically healthy pet dogs were enrolled and randomized either to receive fluralaner at 25-56 mg/kg (Bravecto chewable tablets) on days 0 and 84, or to remain untreated during the D. reticulatus season. Blood samples were collected to evaluate B. canis exposure: on days 0 and 21 (exposure before day 0), during the study and at the end of the tick season (dogs suspected of having become infected after day 0). Efficacy was determined by the percentage reduction in B. canis transmission risk based on the difference in B. canis-positive tests in fluralaner-treated dogs compared with untreated dogs. In addition, ticks collected at monthly intervals throughout the study were identified to species level and females tested for B. canis DNA.
A total of 152 dogs were enrolled in the study, although nine dogs were excluded because they tested positive for B. canis DNA or antibodies within 21 days after enrollment. During the study period, no fluralaner-treated dog became positive for B. canis, resulting in calculated efficacy of 100%. However, babesiosis infection was diagnosed in five untreated control dogs (Fisher's exact test, left-sided, P = 0.0312). Tick analyses revealed that one sample collected in Hungary was infected with B. canis.
Oral administration of Bravecto chewable tablets at the recommended dosage to dogs completely prevented B. canis transmission under field conditions in an endemic area for 12 weeks.
在受控环境下，异恶唑啉类氟虫腈可有效预防感染性硬蜱传播犬巴贝斯虫，预防时间长达 84 天。本研究旨在评估氟虫腈咀嚼片在自然条件下的流行地区对犬持续预防犬巴贝斯虫感染的有效性。
在欧洲，招募了私人拥有的、临床健康的宠物犬，并随机分为两组，一组在第 0 天和第 84 天接受氟虫腈 25-56mg/kg（倍虫净咀嚼片），另一组在硬蜱季节不接受治疗。采集血液样本评估犬巴贝斯虫暴露情况：第 0 天和第 21 天（暴露于第 0 天之前）、研究期间和硬蜱季节结束时（第 0 天之后怀疑感染的犬）。通过比较氟虫腈治疗犬与未治疗犬的犬巴贝斯虫阳性检测率差异，计算出犬巴贝斯虫传播风险降低的百分比，以此确定疗效。此外，每隔一个月收集研究期间采集的硬蜱并鉴定到种水平，检测雌性硬蜱的犬巴贝斯虫 DNA。
共有 152 只犬参与了研究，但有 9 只犬因在入组后 21 天内检测到犬巴贝斯虫 DNA 或抗体而被排除。研究期间，未治疗的对照组有 5 只犬被诊断出感染了犬巴贝斯虫（Fisher 确切检验，左侧，P=0.0312）。而接受氟虫腈治疗的犬均未检测到犬巴贝斯虫。通过对硬蜱的分析发现，在匈牙利采集的一份样本感染了犬巴贝斯虫。
在流行地区，按照推荐剂量给犬口服倍虫净咀嚼片可在 12 周内完全预防犬巴贝斯虫的传播。
