Farm Animal Welfare

Farm Sheep: Liver Fluke in Sheep Welfare

Liver fluke causes significant welfare harm in sheep through liver damage, anaemia, and wasting, with strategic management essential for control.

Key Facts

Fasciola hepatica causes both acute and chronic liver fluke disease in sheep
Acute fluke from high-level infection in autumn causes sudden death in previously healthy animals
Chronic fluke causes progressive weight loss, bottle jaw, anaemia, and vulnerability to secondary infection
The mud snail intermediate host requires wet ground for survival, making fluke risk weather-dependent
Resistance to triclabendazole is emerging in sheep fluke populations in some regions

Welfare Considerations

Liver fluke disease causes significant welfare harm through acute hemorrhagic hepatitis causing sudden death, or chronic liver destruction causing prolonged malnutrition, weakness, and secondary disease. Strategic treatment based on diagnostic testing and knowledge of local fluke risk avoids the resistance selection pressure of calendar-based blanket treatment while maintaining welfare protection.

What You Can Do

Assess local fluke risk annually based on weather and snail habitat
Use faecal egg counts and blood tests to guide treatment timing
Work with your vet to select effective anthelmintics and check for resistance
Fence wet areas to reduce sheep exposure to high-risk snail habitat
Record fluke-associated mortality and treatment outcomes as welfare indicators