The IHN disease (infectious haematopoietic necrosis) is caused by a rhabdo virus.
According to EU legislation, IHN is classified as a class C animal disease in rainbow trout, salmon, trout, arctic char, brook trout, lake trout and pike ((EU) 2018/1882) (of the species occurring in Finland). Other animals apart from fish cannot become infected by the virus and eating fish affected by the disease does not cause any health risks to people or other homeothermic animals, such as dogs or cats.