The liver fluke, Fasciola hepatica, is a highly pathogenic flatworm parasite of ruminants, mainly sheep and cattle. It causes severe liver damage, especially in sheep and can result in the sudden death of previously healthy animals. The disease is also responsible for considerable economic losses, estimated at ~£50m in Scotland alone, due to direct production losses, poor reproductive performance and livers condemned at slaughter. The disease appears to be on the increase in the UK and spreading into previously fluke-free areas, possibly as a result of recent climate change (milder winters and wetter summers) favouring the parasite and its mud snail intermediate host.
Control of fluke has historically involved the strategic application of flukicidal drugs, however, this approach is not thought to be sustainable in the face of increasing reports of flukicide resistance. Diagnosis of fluke is also not straightforward. Faecal egg counting is not a reliable indicator of infection and immunological tests do not discriminate between current and previous infections. Also, there is no vaccine available against fluke.
NADIS publishes a monthly Parasite Forecast for farmers and livestock keepers, based on detailed Met Office data. The Parasite Forecast outlines the parasitic challenge facing cattle and sheep in the different UK regions.
Here at Moredun, we have recently initiated research aimed at: