Liver fluke (Fasciola hepatica) is a parasitic flatworm affecting cattle and sheep, causing clinical disease ranging from mild production loss to acute fatal haemorrhagic hepatitis.
Liver fluke causes welfare harm ranging from subclinical chronic loss of condition to acute fatal disease. Animals with subclinical fluke burden experience reduced feed conversion, suppressed immune function, and reduced productivity - welfare impacts that are real but difficult to observe without clinical signs. Animals with acute fluke disease suffer haemorrhagic hepatitis - a rapidly fatal condition preceded by abdominal pain and distress. Strategic fluke testing and treatment, combined with pasture management that reduces snail habitat, are the most welfare-positive management approaches. Emerging triclabendazole resistance makes integrated control strategies increasingly important.