Liver fluke is a parasitic disease of cattle and sheep causing chronic debilitation and acute death that has expanded its range in response to wetter conditions and represents a significant ongoing welfare burden.
Liver fluke causes suffering that spans from acute crises to years of chronic ill-thrift. Acute fluke in sheep causes sudden death from massive liver hemorrhage — a rapid end but often occurring across significant numbers of animals simultaneously. Chronic fluke in cattle causes progressive decline over months: weight loss despite adequate feed intake, pallor from anemia, and eventually the distinctive protein deficiency causing fluid accumulation under the jaw. The animal cannot eat its way out of this deterioration because the damage to liver function prevents adequate nutrient processing. Flukicide resistance threatens our ability to control this disease pharmacologically, making drainage improvement and strategic treatment increasingly important.