A case of avian flu has been detected in a swan in Co Derry. The H5N8 strain of the virus was confirmed after tests on the dead bird found at Lough Beg.
Chief veterinary officer for Northern Ireland Robert Huey said the discovery was not a surprise, given recent cases in Britain and the Irish Republic.
He urged owners of poultry businesses to step up biosecurity precautions to prevent the disease entering their flocks.
The risk to public health from the H5N8 strain of bird flu is classified as very low, with a very low food safety risk, but the virus would have a significant adverse impact on the industry if it was detected in commercial poultry operations.
Dr Huey said: "This detection in Northern Ireland is not surprising as there have been two recent confirmed cases of highly pathogenic avian influenza in poultry in Great Britain.
"There have also been three confirmed cases of H5N8 in wild birds across England and a falcon in Co Limerick has tested positive in recent days."
Dr Huey said the risk to poultry in Northern Ireland was "moderate". He said biosecurity levels on individual sites was a crucial mitigation factor.
"Veterinary officials continue to monitor the situation across Great Britain and the Republic of Ireland and in consultation with stakeholders will determine the necessary next steps to mitigate for an avian influenza incursion in poultry here," he said.
"If avian influenza were to enter our Northern Ireland flock, it would have a significant impact on our poultry industry, international trade and the wider economy."
Meanwhile Belgium has detected an outbreak of bird flu, leading authorities there to order all poultry farmers and individual bird owners to keep the animals confined.
"Three wild birds that stayed in a bird sanctuary in Ostend tested positive for the H5N8 virus," the country's food safety agency AFSCA said in a statement.
"All gatherings of poultry and birds are strictly prohibited," the statement said, adding that preventive measures were imposed on professional pigeon farms on 1 November.
France this month ordered measures for poultry farms such as protective netting to prevent contact with wild birds that spread the disease, after the country's ministry of agriculture warned that bird flu infections were on the rise in western Europe.
