Liver fluke infestation affects millions of cattle annually. The combination of acute and chronic disease forms causes significant suffering that peaks in winter following wet grazing seasons.
Liver fluke causes significant welfare compromise across the spectrum from acute to chronic disease. Acute fluke disease in heavily exposed cattle causes rapid deterioration with abdominal pain, depression and sudden death - animals that appeared normal can be found dead without obvious prior illness. Chronic disease causes insidious deterioration over weeks and months - cattle lose weight despite adequate feeding, develop anaemia causing exercise intolerance and pallor, and show depression and reduced social engagement. The diagnosis of liver fluke at slaughter through condemned livers reveals the scale of subclinical disease in cattle - a significant proportion of cattle going to slaughter have liver damage indicating fluke infection during their lives. Treatment with appropriate flukicides at strategic times reduces but does not eliminate welfare impacts given treatment timing limitations.