The greylag goose was found in Lurgan Park, Co Armagh, and was reported to Department of Agriculture, Environment and Rural Affairs (DAERA) as part of its dead wild bird surveillance programme.
The animal was sent to the Agri-Food and Biosciences Institute (AFBI), where initial testing has indicated avian influenza sub-type H5N6.
This is the second case of the virus strain reported in the province. A wild buzzard was found in Co Antrim in March this year which also tested positive for H5N6.
“It emphasises the requirement for all bird keepers to remain vigilant and to critically review their biosecurity measures,” said chief veterinary officer for Northern Ireland Dr Robert Huey.
“While the risk of an avian influenza incursion in wild birds remains, the risk to poultry is low.
“However, it is essential that we take the necessary steps to protect our poultry industry, international trade and the wider economy.
All bird keepers are asked to register their flocks to the Department, so they can be contacted in the event of an avian disease outbreak."
The Department also encourages all bird keepers to subscribe to the avian influenza text service by simply texting BIRDS to 67300.
Members of the public are encouraged to report dead waterfowl or gulls, or five or more dead wild birds of other species in the same location, to the DAERA helpline on 0300 200 7840.
Third wild bird flu case confirmed
Second case of bird flu confirmed in Ireland