The British Veterinary Association urged pet-owners not to panic today after news emerged that the deadly H5N1 strain of bird flu had been confirmed in a cat in Germany.

The dead cat was found on the island of Ruegen in the Baltic Sea, home to dozens of H5N1-infected wild birds, the Friedrich Loeffler institute said. It was the first time that the virus has been positively identified in Europe in an animal other than a bird.

More than 90 people in Asia and Turkey have died after contracting the H5N1 virus from infected poultry, but although the virus is gradually spreading across mainland Europe, there have been no cases of human infection.

The first known infection of cats with bird flu came in 2004 when more than 20 tigers and a leopard died after being fed infected poultry carcases. Several domestic cats were also infected.

A study that same year at the Erasmus Medical Centre in Rotterdam demonstrated not just that cats could contract bird flu but that they could pass it on between themselves.

Writing in the journal Science, the Dutch researchers said: "The implications are that, during H5N1 virus outbreaks, domestic cats are at risk of disease or death from H5N1 virus infection, either due to feeding on infected poultry or wild birds, or due to contact with infected cats."

They added that the role of cats in spreading the virus between poultry farms, and from poultry to humans needed to be reassessed and suggested that the presence of the virus in cats could enable the virus to mutate to make it more transmissible between mammals - increasing the risk of a human flu pandemic.

But Dr Freda Scott-Park, president of the British Veterinary Association, said today that the news from Germany should not cause pet-owners to panic and there was no evidence of widespread infection in Thailand of cats or dogs, which can also be infected.

"We're well aware that there is a small risk to other species but basically H5N1 really wants to live in birds; it doesn't really want to live in other species," Dr Scott-Park told Times Online. "The last thing we want to happen is for pet-owners to say right I want my cat or my dog put down now because it might have bird flu."

Of the risk that feline transmission could help the virus to mutate, Dr Scott-Park added: "As far as I know there is no evidence of cats being the mixing vessel. We recognise in the past that pigs have been the mixing vessel with previous avian viruses and it would be the transfer to pigs that we would be much more worried about."

Her message was backed up by Thomas Mettenleiter, head of the German institute which identified the virus in the dead cat. He said: "It has long been known from Asia that cats can be infected if they eat infected birds. An infection of humans, which theoretically cannot be ruled out, could probably only occur with very intimate contact to infected animals."

New of the cat's infection came as the Government's Chief Scientific Adviser admitted that bird flu would remain for at least five years.