Treatment against salmon-lice remained in 2018, as in previous years, the major fishhealth related challenge in Norwegian aquaculture. The health- and welfare consequences of salmon-lice treatment relate mainly to the acute and often fatal injuries associated with the treatments
Besides the salmon louse, the viral diseases dominate the disease situation. Cardiomyopathy syndrome (CMS) appears to be of increased importance nationwide. In addition, pancreas disease (PD) is important in endemic areas. Infectious salmon anaemia (ISA) is catastrophic for infected farms. The bacterial disease yersiniosis, which has been particularly problematic in Mid-Norway, appears now to be under better control.