May cause high mortality on some salmon farms.
Mortality is variable.
Few outward signs. Interior lesions are not always grossly visible but may include hemorrhaging on the kidney and other organs, swollen eyes, fluid in the body cavity, swelling of kidney, pale gills, darkening of the posterior gut and swelling of the spleen. Sea lice can transmit ISAv from infected to susceptible fish. Chlorine and iodine are toxic to fish and shellfish, neutralization with sodium thiosulphate is recommended. Department of Fisheries and Oceans.