Henriksen S A, Andersen C P
Nord Vet Med. 1979 Nov;31(11):455-61.
On the basis of routine diagnostic examinations of 12424 bovine faeces samples for larvae of Dictyocaulus viviparus, performed during the period 1963 through 1977, some calculations and reflections have been made on the incidence and epidemiology of lungworm infection in cattle in Denmark. It seems justified to conclude that dictyocaulosis is an important disease in heifers and cows as well as in calves. A distinct seasonal variation in the incidence of lungworm infection is apparent, in that more than 85% of the faeces samples were submitted within the period July through October. Lungworm larvae could be demonstrated in faeces samples from cattle during the winter and spring- This is considered to be of great importance with a view to re-establishment of the infection in the following grazing season. Overwintering of larvae on pastures seems possible. too, since patent infections among calves were demonstrated already in May and June. A comparison of meteorological data with totals of samples submitted and with relative numbers of positive samples seems to confirm, that both the level and the spread of lungworm infections are influenced by the amount of rainfall during the period June through August.
在1963年至1977年期间，对12424份牛粪便样本进行了常规诊断检查，以检测胎生网尾线虫的幼虫。在此基础上，对丹麦牛肺线虫感染的发病率和流行病学进行了一些计算和思考。可以合理地得出结论，网尾线虫病在小母牛、母牛以及犊牛中都是一种重要疾病。肺线虫感染发病率存在明显的季节性变化，超过85%的粪便样本是在7月至10月期间提交的。在冬季和春季的牛粪便样本中也能检测到肺线虫幼虫。考虑到在下一个放牧季节重新感染的情况，这被认为非常重要。幼虫在牧场上越冬似乎也是可能的，因为在5月和6月就已经发现犊牛中有显性感染。将气象数据与提交样本总数以及阳性样本相对数量进行比较，似乎可以证实，6月至8月期间的降雨量会影响肺线虫感染的程度和传播范围。
