Stewart V A, Hepler D I, Grieve R B
Department of Pathology, Colorado State University, Fort Collins 80523.
Am J Vet Res. 1992 Dec;53(12):2274-7.
Although cats are less susceptible to infection with Dirofilaria immitis than are dogs, the possibility of severe consequences from infection or adulticidal treatment renders preventive treatment a desirable alternative in endemic areas. To evaluate the efficacy of milbemycin oxime as a chemoprophylactic agent in cats, 48 cats were inoculated with infective D immitis larvae. Single oral treatment with 2.3 mg of milbemycin oxime (0.5 to 0.9 mg/kg of body weight) at 30 or 60 days after inoculation with infective larvae gave strong but incomplete protection. Treatment at 60, as well as 90, days after inoculation with infective larvae was completely effective in preventing development of infection. A control group of inoculated, but untreated, cats was monitored biweekly for hematologic changes and for changes in parasite-specific serum antigen and antibody concentrations. Pronounced increases in total leukocyte counts and eosinophil numbers were associated with the estimated time of in vivo molting from fourth- to fifth-stage larvae. Antibody reactivity correlated with infection status, but serum antigen concentrations through 161 days after inoculation were undetectable.
尽管猫比狗更不易感染犬恶丝虫，但感染或成虫杀灭治疗导致严重后果的可能性使得在流行地区进行预防性治疗成为一种理想的选择。为了评估米尔贝肟作为猫化学预防剂的疗效，给48只猫接种了感染性犬恶丝虫幼虫。在接种感染性幼虫后30天或60天，单次口服2.3毫克米尔贝肟（0.5至0.9毫克/千克体重）可提供强大但不完全的保护。在接种感染性幼虫后60天以及90天进行治疗，可完全有效地预防感染的发展。对接种但未治疗的猫组成的对照组每两周监测一次血液学变化以及寄生虫特异性血清抗原和抗体浓度的变化。总白细胞计数和嗜酸性粒细胞数量的明显增加与体内从第四期幼虫到第五期幼虫的蜕皮估计时间相关。抗体反应性与感染状态相关，但接种后161天内血清抗原浓度无法检测到。
