Farmed Salmon Welfare: Infectious Diseases and Prevention Strategies

Infectious diseases including ISA virus, amoebic gill disease, and bacterial infections cause significant mortality and welfare harm in farmed salmon. Prevention through biosecurity and vaccination is the primary welfare strategy.

Key Facts

Infectious salmon anaemia (ISA) is a notifiable disease causing severe respiratory failure, hemorrhage, and death in Atlantic salmon
Amoebic gill disease (AGD) caused by Neoparamoeba perurans is the most significant gill health challenge in sea cage salmon
AGD causes gill damage, respiratory compromise, reduced welfare, and significant production losses
Freshwater treatment is the standard AGD management approach but requires handling stress through pump and bath systems
Pancreas disease (PD) caused by salmonid alphavirus is widespread in European salmon farming and causes significant tissue damage
Vaccination programs have largely eliminated bacterial septicemias from European salmon farming, eliminating the need for prophylactic antibiotics
Biosecurity protocols including site fallowing, single-year-class management, and regulated movement of fish reduce disease transmission
Water temperature management is critical - warm temperatures accelerate most pathogen lifecycles and reduce salmon immune function

Welfare Considerations

Disease in farmed salmon represents one of the most significant welfare challenges in aquaculture - animals experiencing respiratory compromise, tissue damage, or systemic infection suffer in ways that behavioral welfare science is only beginning to characterize. Prevention through vaccination, biosecurity, and environmental management is both more effective and more welfare-positive than treatment after disease establishment. The remarkable success of vaccination in eliminating bacterial disease from European salmon farming demonstrates what targeted prevention programs can achieve. Extending this success to viral and parasitic diseases through ongoing research and implementation represents the most impactful welfare improvement pathway available in the sector.

What You Can Do

Choose salmon from certified farms with documented vaccination programs and disease management plans
Advocate for disease management welfare standards to be included in aquaculture certification requirements
Support research into effective vaccines and prevention strategies for the most welfare-significant salmon diseases
Donate to organizations developing and advocating for disease prevention welfare standards in aquaculture