Liver Fluke and Sheep Welfare: Management Guide

Key Welfare Considerations

• Fasciola hepatica causes acute, subacute, and chronic fluke disease with varying but significant welfare impacts.
• Acute fluke disease from massive infection causes sudden death and severe welfare emergency in young sheep.
• Subacute fluke causes welfare deterioration through weakness, anaemia, and submandibular oedema (bottlejaw).
• Chronic fluke reduces body condition, wool quality, and reproductive welfare performance.
• Liver damage from migrating and adult flukes causes long-term welfare hepatic impairment.
• Wet conditions and flooding promote Galba truncatula mud snail intermediate host populations.
• Pasture management draining wet areas reduces snail habitat and welfare fluke transmission.
• Strategic anthelmintic treatment timing using fluke forecasts reduces welfare disease burden.
• Triclabendazole kills all stages including early immature flukes — welfare treatment of choice for acute disease.
• Closantel and nitroxynil are effective against mature and late immature flukes for welfare management.
• Albendazole treats adult flukes with broader-spectrum welfare benefit against other parasites.
• Triclabendazole resistance is emerging — welfare rotation of active ingredients supports efficacy.
• Bulk milk tank ELISA testing in dairy flocks monitors welfare fluke prevalence at herd level.
• Liver condemnation at slaughter provides welfare fluke prevalence data for farm management.
• Integrated fluke management combining pasture drainage, snail control, and strategic treatment optimises welfare.