The endosymbiont bacteria Wolbachia plays an important role in the pathogenesis and inflammatory immune response to heartworm (Dirofilaria immitis) infection in dogs. Doxycycline is used to reduce Wolbachia from all life stages of heartworm to avoid large releases of the bacteria during the death of the worms. However, the dose and duration currently recommended have been extrapolated from the treatment of other rickettsial infections. Therefore, the aim was to study the dynamics of Wolbachia IgG antibodies in heartworm-infected dogs under adulticide treatment using different dosages of doxycycline. Forty-nine heartworm-infected dogs were recruited. On day 0 (diagnosis), monthly ivermectin (6 μg/kg) was prescribed, as well as daily doxycycline for 30 days, at 10 mg/kg/12 h (n = 13), 5 mg/kg/12 h (n = 19), and 10 mg/kg/24 h (n = 17). Dogs underwent adulticide treatment and blood samples were collected on days 0, 30, 90, and 120. All dogs had antibodies against recombinant Wolbachia surface protein (rWSP), confirming the important role of the bacteria in heartworm. No significant differences were found in anti-rWSP response by presence/absence of microfilariae, or by parasite burden on day 0. In all treated groups, the anti-rWSP antibody response was not significantly different between days 0 and 30 but was significantly lower between days 0 and 120 (p < 0.05). The results of the present study suggest that the administration of a lower dose than currently recommended is sufficient to achieve a significant reduction of Wolbachia in dogs infected by D. immitis.

内共生细菌Wolbachia在犬的心丝虫（Dirofilaria immitis）感染的发病机理和炎性免疫应答中起重要作用。强力霉素用于减少丝虫整个生命阶段的沃尔巴氏菌，从而避免在丝虫死亡期间大量释放细菌。但是，目前推荐的剂量和持续时间已从其他立克次氏菌感染的治疗中推算得出。因此，目的是研究沃尔巴克氏菌的动力学在使用不同剂量的强力霉素进行成年杀虫剂处理的犬丝虫感染犬中，IgG抗体。招募了49只经心丝虫感染的狗。在第0天（诊断），开出每月伊维菌素（6μg/ kg）的处方，并每日强力霉素30天，分别为10 mg / kg / 12 h（n = 13），5 mg / kg / 12 h（n = 19）和10 mg / kg / 24 h（n = 17）。对狗进行了成年杀灭剂治疗，并在第0、30、90和120天收集了血样。所有狗均具有针对重组Wolbachia的抗体表面蛋白（rWSP），证实了细菌在丝虫中的重要作用。在第0天，是否存在微丝虫病或寄生虫负担对r-rWSP抗体反应无显着差异。在所有治疗组中，第0天和第30天的抗rWSP抗体反应无显着差异，但在第0天和第30天之间均显着降低第0天和第120天（p <0.05）。本研究的结果表明，比目前推荐的剂量低的剂量足以使D. immitis感染的狗的Wolbachia明显减少。