Cat owners in countries hit by bird flu should keep their pets indoors, two agencies involved in co-ordinating the fight against the virus have said.
Stray cats may help to spread the H5N1 strain of bird flu, experts say
The World Health Organization and the Food and Agriculture Organization's advice follows the death of a domestic cat in Germany of the H5N1 strain.
The death is the European Union's first known case of cross-species infection.
Both organisations said that despite the finding, cats were not believed to play a major role in the virus' spread.
The agencies said they were mindful of the potential for flu viruses to mutate into strains lethal to humans or other mammals.
The FAO recommendations focus on how to minimise risk in areas where H5N1 has been diagnosed or is suspected among poultry or wild birds.
- Report unusually high numbers of bird deaths
- Inform local vets of any dead or sick cats
- Keep cats away from wild birds or poultry, keeping them indoors if necessary
- If cats bring sick or dead birds into the house use plastic gloves to put the birds in a plastic bag for collection by vets
- Keep away from stray cats and do not touch sick or dead cats or other animals.
The WHO also advises keeping dogs on leads at all times outside home premises, and not to feed any "water birds".
Cats have been known to contract the virus from eating infected birds. Three rare civet cats in Vietnam died of bird flu last August. In October 2004, dozens of tigers died at a private zoo in Thailand after a bird flu outbreak.
Tests have confirmed that the virus can cause severe illness in domestic cats and can be passed between them.
COMBATING BIRD FLU
Report unusual bird deaths
Report sick or dead cats
Keep cats away from birds or indoors
Avoid stray cats
Keep dogs on leads outdoors
Use gloves to put dead birds in bags
Wash hands frequently
Clean litter trays and feeding dishes regularly
Experts believe the dead cat in Germany ate infected poultry, but they point out it is possible animals could contract the disease by inhaling contaminated faeces.
While there is no evidence of cat-to-human infection, the authorities acknowledge it is a "small possibility".
An FAO spokesman said: "Humans and other mammals need to come into contact with large amounts of virus to become infected.
"And in cases of infection with H5N1, mammals and humans apparently only shed small amounts of virus, contributing to reduced risk of spread among themselves."
Officials are urging people to take hygiene precautions including frequent hand-washing with soap and water.