Liver fluke causes severe welfare and production losses in sheep, and emerging resistance to triclabendazole threatens the primary treatment option.
Acute fasciolosis causes intense suffering and rapid death: lambs dying from acute fluke disease experience internal haemorrhage as large numbers of immature flukes migrate through liver tissue. Subacute and chronic disease causes prolonged debilitation including anaemia, hypoproteinaemia, and immunosuppression that predispose to secondary infections. Bottle jaw from protein loss is painful and disfiguring. As triclabendazole resistance renders the most effective treatment ineffective in many flocks, producers face increasing welfare challenges. Strategic fluke testing, alternative flukicide use, and integration of snail habitat management are essential welfare-protective responses to the resistance challenge.