The United Nations Food and Agriculture Organization (FAO) said today that cats should be monitored for signs of bird flu or avian influenza.

They said that cats, like humans, can become infected with the deadly strain of the H5N1 virus that causes avian flu, possibly from eating infected birds, or from being in very close contact with infected birds or their feces. But they emphasize there is no evidence of a sustained cat to cat transmission or of cats passing the deadly strain to humans.

They mention that people have become alarmed by reports that cats in Indonesia have become infected with the deadly version of H5N1 from scavenging on dead and sick infected birds near markets in Java and Sumatra where H5N1 avian flu has recently been detected.

Meanwhile the US embassy in Indonesia has advised its citizens to keep away from stray cats as a precaution against becoming infected with lethal H5N1. They said that they had received confirmation of wild and stray cats carrying the deadly virus.

The FAO is advising that cats should be kept away from infected birds wherever possible. And where poultry is being raised on a commercial basis, cats should be kept indoors.

The FAO does not advise culling cats as a safety measure against the spread of lethal H5N1.

At the moment the strategy is simply to reduce the opportunity for the virus to move into a cat population on a sustained basis where it might mutate into a strain that could infect humans or cause widespread infection in the cat population.

Assistant Director-General of the FAO, Alexander Müller, put it like this, "cats could act as intermediary hosts in the spread of the H5N1 virus between species," and he added that "growth in cats might help the H5N1 virus to adapt into a more highly infectious strain that could spark an influenza pandemic."

Also, said the FAO, culling cats would lead to a surge in the rat population, and vastly increase the infection rate of serious diseases that rats already pass on to humans.

Previous incidents of cats being infected have occurred in Thailand, Russia, Iraq, Turkey and other countries in the EU.

According to the FAO, findings in Indonesia in January showed that 80 per cent of the cats in the areas affected by the H5N1 outbreak were not infected. This is encouraging news because it is evidence that the virus has not found a reservoir in which to sustain itself in the cat population. "Cats are more likely to be a dead-end host for the H5N1 virus," said FAO Animal Health Officer, Peter Roeder.

The FAO urges people in areas affected by H5N1 to be vigilant and assume that any unusual deaths in their local cat population could be due to bird flu. Roeder said that "The observation of cats should therefore become part of surveillance systems in affected areas."

The FAO is working with scientists in affected countries to find out exactly how the virus gets into cats, how long it stays there and what might be the most likely infection routes to other animals.

It is important to distinguish between the lethal strain of H5N1, and other much milder versions. Many mammal species get infected with the milder version of H5N1, such as pigs, cats, dogs, mice, ferrets, and rabbits.

What the FAO are essentially saying is that if you live in an area where you know the deadly strain has been found and you know of a cat that is seriously ill or has died of bird flu, then you should report it. In the meantime keep an eye or your own cat and if you have a poultry farm near an infected area, keep your cats indoors.

There is no suggestion that pet owners should be having their pets put down in case they have got or may catch the deadly H5N1 virus. Animals get all kinds of flu and there are shots against flu for pets. If you think your pet has flu take it to your local veterinary clinic.

Click here for more FAO Animal Health Information on H5N1 infection in cats and other animals.

Click here for recent CDC scientific study "Subclinical Infection with Avian Influenza A (H5N1) Virus in Cats".