Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, 158 Magruder Hall, Corvallis, OR 97331, USA.
Vet J. 2013 Aug;197(2):233-7. doi: 10.1016/j.tvjl.2013.01.003. Epub 2013 Feb 9.
Dairy cattle are becoming increasingly complicated to treat in the USA due to the great limitation of approved drugs. Additionally, most drugs require withdrawal times for milk that are not viable for treating entire dairy herds. The objective of this field trial was to determine the efficacy of eprinomectin, one of only two parasiticides approved for lactating dairy cattle, for eradication of naturally occurring chorioptic mange on a commercial dairy farm. All animals present on the farm were treated on the same day and, later, new animals introduced to the premises were treated on arrival. All cows were re-treated at dry-off. Lesion scoring was performed five times over a period of 12 months. A reduction in the proportion of cows with lesions was apparent 3 months after treatment and, although the proportion stayed low, it increased again at 12 months post-treatment. Logistic regression to evaluate factors associated with the presence of mange lesions showed that older cows, late lactation, and recent treatment, were associated with presence of lesions. It also showed that multiple treatments (whole-herd treatment and at dry-off) helped to reduce the presence of lesions. No increase in milk production could be measured, but animal wellbeing improved. The results of this study show that chorioptic mange can be controlled in entire herds, although multiple treatments will be required to potentially eradicate the parasite. The value of the study is that it shows that mange can be controlled in dairy cattle with approved drugs, eliminating the need to use non-approved agents.
由于批准的药物有很大的局限性，美国的奶牛治疗变得越来越复杂。此外，大多数药物需要奶牛停止产奶一段时间，这对于治疗整个奶牛群来说是不可行的。本现场试验的目的是确定多拉菌素（伊维菌素的一种）的疗效，多拉菌素是仅有的两种批准用于泌乳奶牛的驱虫剂之一，用于根除商业奶牛场自然发生的痒螨病。农场所有动物都在同一天接受治疗，后来，新引进的动物到达时也接受了治疗。所有奶牛在干奶期都进行了再治疗。在 12 个月的时间里，对病变评分进行了五次。治疗后 3 个月，病变奶牛的比例明显下降，尽管比例较低，但在治疗后 12 个月又再次上升。通过逻辑回归评估与痒螨病存在相关的因素表明，年龄较大的奶牛、泌乳后期和最近的治疗与病变的存在有关。它还表明，多次治疗（全群治疗和干奶期治疗）有助于减少病变的发生。虽然无法测量产奶量的增加，但动物的健康状况有所改善。本研究结果表明，尽管可能需要多次治疗才能根除寄生虫，但可以控制整个牛群的痒螨病。该研究的价值在于它表明可以用批准的药物控制奶牛的痒螨病，从而无需使用未经批准的药物。
