McKenna P B
Batchelar Animal Health Laboratory, P.O. Box 536, Palmerston North, New Zealand.
N Z Vet J. 1996 Apr;44(2):73-5. doi: 10.1080/00480169.1996.35938.
Larval cultures were used to determine the identities and occurrences of those parasites (excluding Nematodirus) represented by strongylid eggs at the time of anthehnintic administration in ovine faecal egg count reduction tests submitted to the Batchelar Animal Health Laboratory between 1992 and 1994. The numbers of individual nematode genera recorded in pre-treatment samples from these cases ranged from one to five and included infections of Haemonchus, Ostertagia, Ttichostrongylus, Cooperia and Oesophagostomum/Chabertia. Adequate egg representation for testing purposes by all five genera simultaneously was found to occur in only 17 (10%) of the 163 cases examined, with the majority (71%) of them containing between one and three nematode genera. The greatest representation occurred in those tests conducted during the months of February to May. However, even during this period, worm eggs of all five genera were concurrently present on only 16% of occasions. The importance of knowing what nematode genera are adequately represented at the time of routine faecal egg count reduction testing and the relevance of this information to reducing the likelihood of being misled when under- taking assessments of farm resistance status are discussed.
在1992年至1994年间提交给巴彻勒动物健康实验室的绵羊粪便虫卵计数减少试验中，幼虫培养用于确定驱虫药给药时由圆线虫卵代表的那些寄生虫（不包括细颈线虫）的种类和出现情况。这些病例治疗前样本中记录的单个线虫属数量从1到5个不等，包括血矛线虫、奥斯特他线虫、毛圆线虫、古柏线虫和食道口线虫/夏伯特线虫感染。在163例检查病例中，发现只有17例（10%）同时出现了所有五个属的足够用于测试目的的虫卵，其中大多数（71%）含有1至3个线虫属。在2月至5月期间进行的那些试验中出现的代表性最强。然而，即使在此期间，所有五个属的虫卵也仅在16%的情况下同时出现。本文讨论了在常规粪便虫卵计数减少试验时了解哪些线虫属有足够代表性的重要性，以及该信息与降低在评估农场抗性状态时被误导的可能性的相关性。
