Liver fluke (Fasciola hepatica) is a parasite causing significant welfare harm in sheep and cattle. Climate change is expanding the geographic range of fluke, making welfare-positive management increasingly important.
Liver fluke welfare is both an acute emergency risk and a chronic welfare challenge. Acute outbreaks can kill sheep suddenly and in numbers, with visible suffering in affected animals. Subacute and chronic disease causes prolonged malnutrition, immune compromise, and secondary infection - sustained welfare harm that is harder to observe and quantify than acute disease. Welfare-positive management requires regular pasture risk assessment using NADIS fluke forecasting tools, strategic treatment at appropriate times in the fluke cycle, and pasture management that reduces snail habitat where feasible. Emerging triclabendazole resistance requires careful drug selection to preserve treatment options.