Rainbow trout are one of the most widely farmed fish species globally, and disease management practices significantly affect the welfare of millions of individual animals.
Disease events in trout farming involve significant suffering - fish with whirling disease spin uncontrollably and cannot feed, while viral infections cause hemorrhaging and tissue damage. Preventive medicine through good husbandry, vaccination, and biosecurity reduces both disease burden and welfare impacts of treatment. Water quality management is particularly critical, as trout are sensitive to dissolved oxygen, temperature, and ammonia levels that directly affect physiological stress.