Liver fluke A growing threat to UK livestock production

The liver fluke, Fasciola hepatica, is becoming increasingly common in cattle and sheep in the UK. The suitability of different methods for detection of liver fluke infection depends on the type of animal, the purpose of the investigation (individual or herd level) and the stage of the liver fluke life-cycle. Treatment options are also influenced by the type of animal (beef, dairy, sheep) and the fluke's life-cycle and by regulatory issues that determine availability of effective products. To some extent, forecasting of fluke risk at regional or herd level is possible based on weather conditions and farm management. Official guidelines for evaluation of treatment efficacy do not exist, but several methods have been proposed based on reduction in faecal egg counts or coproantigen secretion. Detection of liver fluke infection and treatment efficacy may be compromised by the presence of rumen fluke. The predominant rumen fluke species in the UK has been shown to be Calicophoron daubneyi. This rumen fluke shares an intermediate snail host, Galba truncatula, with the liver fluke, which contributes to the risk of mixed infections. In this paper, we review the respective flukes' lifecycles, their impact on production and health, and diagnostic and control options in cattle and sheep.