Farmers were warned to be vigilant after detecting bluetongue in a cow imported to Northern Ireland.
Bluetongue is a viral disease that is borne by mosquitoes and can affect sheep and cattle.
It was discovered in a heifer that had been imported from France, where the disease is circulating.
The animal has been destroyed and there are movement restrictions on the affected farm.
The Department of Agriculture, Environment and Rural Affairs (DAERA) has not announced its location.
The disease does not affect humans or food safety, but can reduce milk production and cause infertility in affected livestock.
Robert Huey, Chief Veterinarian at DAERA, said the discovery was due to a "rigorous post-import testing program".
"It's very important that we keep the bluetongue off," he said.
"The risk is not just for yourself, but for the industry as a whole, since the impact on trade can be catastrophic."
In addition to the movement restrictions in the farm, the department officials will also track down and test associated herds.
An inquiry was launched to assess the situation. It helps to determine if the disease is circulating.
Experts say that this is "highly unlikely" as the active mosquito period has now passed.
As a result, the United Kingdom is currently officially free of bluetongue diseases.