[Fasciola hepatica: coprological diagnosis in comparison to the worm burden in sheep and cattle].

Abstract

Bulls artificially infected with a varying number of metacercariae of Fasciola hepatica were kept under uniform, standardized laboratory conditions. 6 months after the infection the daily range of variation and the distribution of the Fasciola eggs in the faeces were determined 3 times a day (morning, noon and afternoon) over two test periods, each of 5 days. This test, carried out in over 800 individual faeces samples, showed that the excretion of Fasciola eggs over a period of several days fluctuates considerably within one animal and within one infection group; the excretion of Fasciola eggs over one day varies widely at different times in each animal and also in each infection group; the distribution of Fasciola eggs in the faeces is always irregular within one day and also over several days in all animals. The variations demonstrated here must be taken into consideration when assessing the results of coproscopical diagnosis because studies of the faeces carried out on a single occasion can lead to completely incorrect conclusions being drawn.