Farmed rainbow and brown trout face specific disease challenges that cause significant welfare harm. Understanding disease management enables welfare-conscious trout product choices.
Trout disease welfare, like all aquaculture disease welfare, involves the intersection of prevention failures and inadequate treatment options. PKD progresses slowly - fish develop kidney pathology, become progressively weaker, lose condition, and either die or live in a compromised state for extended periods. The chronic nature of the disease means many affected fish experience welfare degradation for weeks to months. Temperature is a major determinant of PKD severity - climate change is both increasing disease prevalence and creating conditions where therapeutic water temperature reduction (moving fish to cooler water to slow PKD progression) is increasingly difficult. Managing disease welfare requires investment in biosecurity that prevents the disease rather than managing its consequences.