It is the first case of the H5N6 strain in Northern Ireland this year.
Bird flu has been detected in a buzzard in County Antrim.
The H5N6 strain is the first of its kind to be found in Northern Ireland this year although the Department of Agriculture, Environment and Rural Affairs (DAERA) said it was not unexpected.
Chief Veterinary Officer for Northern Ireland Robert Huey said: “The finding further emphasises the requirement for all bird keepers to remain vigilant and to critically review their biosecurity measures, for example, feeding and watering birds under cover to help reduce the risk of their poultry coming in contact with wild birds.
“I continue to encourage strongly all bird keepers to register their flocks. This will ensure they receive the latest information from the Department and also allow them to be contacted in an avian disease outbreak enabling them to protect their flock at the earliest opportunity.”
Martyn Blair, Ulster Farmers’ Union poultry chairman, encouraged producers to practice good farm hygiene and keep birds’ food and water in enclosed areas separate from wild birds wherever possible.
He added: “We strongly recommend that all poultry keepers, including backyard keepers, review their biosecurity measures and familiarise themselves with DAERA’s guidance on good biosecurity.
“If you have any suspicion of disease within your flock you should contact your vet or the local DVO immediately.”
Poultry keepers can sign up to the AI text alert service to receive immediate notification of a disease outbreak by texting BIRDS to 63700.