Disease management in farmed trout requires balancing fish welfare, antibiotic stewardship, and biosecurity to maintain healthy populations.
Sick fish in disease outbreaks experience pathogen-induced suffering including tissue damage, organ failure, and the behavioral effects of immune system activation. Disease outbreaks often cause mass mortality events where thousands of fish die over hours or days. Medical treatment itself involves handling that causes additional stress. The development of effective fish vaccines has been transformative for welfare - Norwegian salmon farms use minimal antibiotics compared to historical levels because vaccines prevent most bacterial diseases. Maintaining biosecurity through equipment disinfection and movement controls prevents disease introductions that would cause widespread suffering.