Criteria for diagnosing anthelmintic resistance by the faecal egg count reduction test

Authors: McKenna PB
Publication: New Zealand Veterinary Journal, Volume 42, Issue 4, pp 153-154, Aug 1994
Publisher: Taylor and Francis

Animal type: Livestock
Subject Terms: Alimentary system/gastroenterology, Animal remedies/veterinary medicines, Anthelmintics, Parasite control, Parasites - internal, Diagnostic procedures, Nematode, Treatment/therapy
Article class: Short Communication

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Abstract: This study examines the possible outcome of adopting criteria recommended by the Australian Working Party for defining anthelmintic resistance by the faecal egg count reduction test, namely a mean percentage reduction of less than 95%, together with a lower 95% confidence limit of less than or equal to 90%. Based on an analysis of 313 veterinary diagnostic cases submitted for faecal egg count reduction testing in sheep and goats over a 7-year period, it was found that lower confidence limits of 90% or less were always associated with mean percentage reductions of less than 95%. These results suggest that if anthelmintic resistance is to be defined on the basis of mean faecal egg count reductions of this magnitude, then little practical purpose is likely to be served by further consideration of the lower confidence limits of these estimates.

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