Government vets have started an investigation after five swans were found dead in Co Down.
A mystery disease is one of the lines of investigation |being pursued by scientists |after the Department of Agriculture and Rural Development (DARD) revealed the discovery was the second of its kind to be probed.
In the previous case lesions were discovered, suggesting some sort of bacterial infection.
However DARD insists there is no evidence to suggest the deaths are part of a rising trend.
The five mute swans were found dead on private land in Killyleagh and it is understood another two birds have fallen ill.
The birds were removed so post-mortem examinations could be carried out.
In April 2006 the avian flu virus H5N1 reached the UK for the first time when a dead whooper swan was found in Scotland.
A spokesman said: “Field officers from DARD veterinary service based at the local office in Newtownards are currently investigating and will send swans to the AFBI laboratories for post-mortem examination.
“The post-mortem will hopefully provide more detailed information and a definitive diagnosis |if the carcasses are not in an |
advanced state of decomposition. We have no evidence to suggest that this is a rising trend at |present.
“This is the second case that has been brought to our attention, the first case was investigated by DARD and the post-mortem revealed lesions suggestive of |bacterial infection.
“We would ask the public to refer to the DARD website or helpline for information on the types of bird deaths that we would like to be brought to our attention so that DARD can monitor the situation and respond quickly.”
If you find five or more dead birds of any species in the same place, the DARD helpline should be contacted on 028 9052 4999.