Liver fluke is a major parasitic disease of cattle and sheep causing significant welfare harm and production losses - climate change is expanding its geographic range in the UK.
Liver fluke welfare in cattle and sheep is increasing as climate change expands risk areas and anthelmintic resistance limits control options. Acute fasciolosis kills rapidly and causes severe suffering during the brief illness period. Chronic fasciolosis causes prolonged welfare harm through weight loss, anaemia and the metabolic cost of managing a large parasite burden. The resistance challenge requires strategic, evidence-based treatment decisions rather than routine preventive treatment that accelerates resistance development. Pasture management addressing drainage and snail habitat reduces exposure without relying entirely on treatment. Farm health planning with veterinary guidance is essential for effective welfare-oriented management.