Disease management in aquaculture involves balancing the welfare harm of disease itself against the welfare and environmental costs of treatment, with prevention offering the most welfare-positive approach.
Aquaculture disease management involves genuine welfare tradeoffs where the welfare harm of treatment must be compared with the welfare harm of untreated disease. Norwegian salmon aquaculture demonstrates that vaccination can transform disease management — by virtually eliminating bacterial diseases that previously required extensive antibiotic treatment, vaccination simultaneously reduced disease burden, treatment stress, and antibiotic resistance risk. This model of prevention-focused disease management represents the welfare-optimal approach. Where treatment is necessary, minimizing handling stress and optimizing treatment protocols reduces welfare harm. The disease-treatment welfare dilemma in aquaculture underlines the importance of system design that prevents disease through appropriate stocking density, water quality, and biosecurity rather than relying on reactive treatment.