Foie gras production requires force-feeding ducks and geese to enlarge their livers to pathological sizes. It is one of the most thoroughly documented cases of deliberate animal suffering in food production.
Foie gras production provides one of the clearest cases where scientific evidence of animal suffering has been systematically documented. Birds show increased corticosterone (stress hormone) levels during force-feeding periods, active avoidance of feeders, and behavioral indicators of chronic stress. The esophageal tube insertion causes physical trauma, particularly as the procedure frequency intensifies. The massively enlarged liver - the desired product - is a genuine pathology causing abdominal pressure, difficulty breathing, and sometimes liver rupture. Despite this evidence, foie gras remains legal and consumed as a luxury product in France, the US (except California), and other markets, reflecting how cultural tradition and economic interest can override welfare science.