Roby T O, Simpson J E, Amerault T E
Am J Vet Res. 1978 Jul;39(7):1115-6.
A long-acting formulation of oxytetracycline (L-200) was injected at a dose level of 20 mg/kg intramuscularly into 12 yearling cattle that had been experimentally inoculated with Anaplasma marginale 64 days previously. Four cattle were treated twice, 4 were treated 3 times, and 4 were treated 4 times. All injections were given once ever 7 days. Previous work (unpublished) with this formulation has revealed prolonged blood values following a single injection. The blood (80 ml) of each calf was inoculated into a susceptible test calf 83 days after the last treatment dose. Anaplasmosis did not occur in any of the test calves. Two infected cattle were treated with 12 daily injections of oxytetracycline (L-50) at a dose level of 11 mg/kg to establish the sensitivity of the parasite to oxytetracycline. Subsequent calf inoculation tests showed that A marginale was eliminated. Two unmedicated, infected cattle remained infected throughout the study. Complement-fixation tests with A marginale antigen at 6 months after treatment showed average sera titers of less than 5 in the treated cattle and 45 in the unmedicated cattle.
将长效土霉素制剂（L - 200）以20毫克/千克的剂量肌肉注射到12头一岁小牛体内，这些小牛在64天前已通过实验接种了边缘无形体。4头牛接受了2次治疗，4头牛接受了3次治疗，4头牛接受了4次治疗。所有注射均每7天进行一次。此前关于该制剂的研究工作（未发表）表明，单次注射后血液中的药物浓度会持续较长时间。在最后一次治疗剂量后的83天，将每头小牛的80毫升血液接种到一头易感的试验小牛体内。所有试验小牛均未发生无浆体病。对2头受感染的牛每天注射11毫克/千克的土霉素（L - 50），连续注射12天，以确定寄生虫对土霉素的敏感性。随后的小牛接种试验表明边缘无形体已被清除。在整个研究过程中，2头未用药的受感染牛一直处于感染状态。治疗6个月后用边缘无形体抗原进行补体结合试验，结果显示，接受治疗的牛血清平均滴度低于5，未接受治疗的牛血清平均滴度为45。
