Antibiotic use in aquaculture raises welfare, environmental, and public health concerns. Understanding the relationship between disease, antibiotics, and fish welfare guides better practices.
The relationship between antibiotic use and fish welfare is complex: antibiotics prevent and treat bacterial infections that cause severe welfare harm, but their use in conditions that foster rapid disease spread reflects underlying welfare-compromising management practices. The Norwegian salmon industry's demonstration that antibiotic use can be reduced by over 99 per cent through vaccination and improved management shows that antibiotic dependence is not inevitable in high-intensity aquaculture. The welfare-appropriate approach to antibiotic use treats sick animals promptly while addressing the root causes of disease vulnerability through density management, water quality, nutrition, and genetic selection for disease resistance. Reducing antibiotic use through better welfare practices benefits fish health, the environment, and public health simultaneously.