The Canadian Food Inspection Agency confirmed Saturday afternoon that avian influenza had spread to a fifth Fraser Valley farm, a turkey producer near Abbotsford, B.C.
It is unclear if there is any connection to the other four farms reported earlier this week.
Chickens are being euthanized in Chilliwack, and that will continue all weekend. The agency says it will use CO2 gas and then compost the remains.
Owners of the first four farms with cases of the H5N2 will be compensated for the dead birds.
The industry had voluntarily imposed a three kilometre containment zone around the infected farms in an attempt to prevent the virus from moving beyond the first four farms.
The outbreak of the highly-virulent strain of the flu has prompted several Asian countries to ban poultry products from the region or the whole of Canada.