Fasciolosis caused by Fasciola hepatica is a major parasitic disease of sheep worldwide, causing significant welfare harm through liver damage, protein loss, and anaemia. Strategic anthelmintic use, drainage, and grazing management form the most effective integrated control approach.
Sheep with chronic fasciolosis experience weeks to months of progressive debility, including protein-losing hypoalbuminaemia causing characteristic bottle jaw, fatigue, and reduced feed intake. In acute outbreaks, young lambs die within hours to days from massive hepatic haemorrhage. Welfare-centred control requires late summer fluke forecasting using regional climate data, strategic treatment timed to kill incoming fluke before liver damage accumulates, and long-term pasture drainage and fencing of wet areas to reduce snail habitat. Rotating between flukicide classes protects triclabendazole efficacy for cases where it is the only effective option.