Waltner-Toews D, Martin S W, Meek A H
Can Vet J. 1986 Jan;27(1):17-22.
Calf-related drug use was studied on 104 randomly selected Holstein dairy farms in southwestern Ontario between October 1980 and July 1983. About 20% of dairy farmers were observed to administer antimicrobials preventively to healthy newborn calves (primarily as commercial "cocktails" of various antimicrobials, vitamins and minerals given in an oral bolus form) at some time during the year. About 30% of the farmers were observed to use vitamins (primarily vitamins A,D and E) preventively. The pattern of types of antimicrobials used preventively appeared to be different from the pattern seen for therapeutic use. Chloramphenicol was the single most commonly used therapeutic antimicrobial in this population of calves, accounting for some 30% of overall therapeutic antimicrobial use. In this study population, the prophylactic use of antimicrobials was associated with a decreased risk of being treated for pneumonia, and of dying, but an increased risk of being treated for scours. Case fatality rates for calves treated therapeutically varied, depending on the antimicrobial used and the routine of treatment. Calves treated with penicillin consistently suffered the highest case fatality rates. Case fatality rates for calves treated with chloramphenicol were considerably higher for calves treated once per day than for calves treated twice per day. For instance, calves first treated for scours with chloramphenicol, if treated once per day, suffered a case fatality rate of 22%. For scouring calves treated twice per day the case fatality rate was just under five percent. Clinical field trials of specific antimicrobials used preventively and therapeutically are required to delineate the conditions under which they might be useful.
1980年10月至1983年7月期间，在安大略省西南部随机挑选了104个荷斯坦奶牛场，对犊牛用药情况进行了研究。观察发现，约20%的奶农在一年中的某些时候会对健康的新生犊牛预防性使用抗菌药物（主要是以口服大丸剂形式给予的各种抗菌药物、维生素和矿物质的商业“合剂”）。约30%的奶农被观察到预防性使用维生素（主要是维生素A、D和E）。预防性使用的抗菌药物类型模式似乎与治疗用途的模式不同。氯霉素是该犊牛群体中最常用的单一治疗性抗菌药物，约占治疗性抗菌药物总使用量的30%。在本研究群体中，预防性使用抗菌药物与肺炎治疗风险和死亡风险降低相关，但腹泻治疗风险增加。治疗性治疗的犊牛病死率各不相同，取决于所使用的抗菌药物和治疗方案。用青霉素治疗的犊牛病死率一直最高。每天治疗一次的犊牛用氯霉素治疗的病死率比每天治疗两次的犊牛高得多。例如，首次用氯霉素治疗腹泻的犊牛，如果每天治疗一次，病死率为22%。每天治疗两次的腹泻犊牛病死率略低于5%。需要对预防性和治疗性使用的特定抗菌药物进行临床现场试验，以确定它们可能有用的条件。
