Disease is the leading cause of welfare impairment and economic loss in trout aquaculture, requiring integrated management approaches that consider fish wellbeing.
Disease management in trout farming sits at the intersection of economic necessity and welfare responsibility. When disease outbreaks occur, fish may suffer for extended periods before conditions are identified and treatment initiated. Treatment itself can involve stressful handling, chemical baths, or mass culling. A welfare-first disease strategy invests heavily in prevention: optimizing water quality and oxygen levels, maintaining appropriate stocking densities, using available vaccines, selecting disease-resistant genetic lines, and building stockperson skill in early disease recognition. The welfare of fish in disease outbreaks should be factored into treatment decisions — fish experiencing significant suffering from disease that cannot be effectively treated humanely deserve timely euthanasia rather than prolonged deterioration.