Disease management in rainbow trout aquaculture has major welfare implications, with bacterial, viral, and parasitic infections causing significant suffering in farmed populations across the global industry.
Disease management in trout aquaculture intersects directly with welfare because the conditions that promote disease transmission - high density, poor water quality, stress - simultaneously reduce individual fish welfare. Fish experiencing bacterial or parasitic disease suffer pathological changes to body systems, altered behavior indicating discomfort, and immune stress responses. The welfare progress in Norwegian salmon farming, where vaccine development has largely replaced antibiotics, provides a model for other trout-producing regions. Early detection through behavioral monitoring and regular health assessment, combined with optimal rearing conditions that support immune function, represents both good welfare practice and good disease management.