LAUSR

Infections by parasitic flukes are an important animal health and production concern for livestock producers worldwide. In the UK, and throughout the EU, liver fluke (Fasciola hepatica) historically has been a major focus for livestock farmers. However, in recent years, there has been a sharp increase in the incidence of rumen fluke (or paramphistome) infections in both sheep and cattle, such that they are now more common than liver fluke in many areas (1). The predominant rumen fluke species in the UK and Ireland has been confirmed as Calicophoron daubneyi (2), which appears to have spread from mainland Europe where it is common in countries such as France, Spain, and Belgium (1). Although there have been limited reports of Paramphistomum leydeni in Ireland (3, 4) and the Netherlands (5) the importance/pathogenicity of this species has not been investigated. Although the exact reasons for the increase in rumen fluke infections are not fully understood, the increase in warm wet summers and mild winters—conditions that favor Galba truncatula, the confirmed snail intermediate host of both F. hepatica and C. daubneyi—are thought to be the major contributing factor (6). It has also been suggested that C. daubneyi is adapting to out-compete the already endemic F. hepatica in their shared environment and snail intermediate host species (7). Furthermore, the widespread use of fasciolicides, to target liver fluke—most but not all are specific for liver fluke—may be giving C. daubneyi further competitive advantage over F. hepatica, such that C. daubneyi may eventually replace F. hepatica as the most prevalent endemic trematode in the UK/Ireland (8).