Foie gras is produced by force-feeding ducks and geese two to three times daily to massively enlarge the liver, causing physical pain, disease, and distress that has led to production bans in many countries.
Foie gras welfare harms are well-documented by veterinary science. Force-feeding causes oesophageal abrasion and trauma with each insertion of the tube. Rapid liver enlargement causes compressive effects on lungs and other organs, causing dyspnoea and difficulty walking. Birds cannot express normal feeding behaviour, social behaviour, or movement. Post-mortem examination of gavage birds consistently reveals pathological changes indicating disease rather than normal physiological response. The liver enlargement is hepatic steatosis — a disease state — rather than a natural adaptation. The welfare case against foie gras is among the strongest for any food product. Market pressure from bans and consumer refusal has reduced demand and shifted some production toward alternative methods.