Fasciolosis caused by liver flukes (Fasciola hepatica) is a widespread parasitic disease of cattle causing liver damage, production losses, and significant animal suffering in grazing systems.
Liver fluke causes a spectrum of welfare harms. Acute infections in naive animals cause severe pain and rapid deterioration as migrating flukes destroy liver tissue. Chronic infection produces a slower decline — progressive weight loss, protein deficiency causing fluid accumulation, and general debilitation. Affected animals may continue in this state for months before diagnosis. Effective control requires strategic flukicide treatment timed to kill migrating flukes before they reach the bile ducts, combined with pasture management to reduce snail habitat. Faecal egg counting and liver condemnation data at slaughter are useful diagnostic tools for herd-level monitoring.