Scientists have known for at least two years that felines could catch the deadly bird flu virus – it was found in 2004 in Thailand in two domestic cats. Big cats who had been fed infected chicken carcasses in a Thai zoo were also killed by H5N1. And last year, wild civet cats died after contracting the virus.
Cats tend to go for sick birds, so the discovery of the dead German cat in an area where dozens of birds had died from H5N1 does not come as a big surprise. And according to a 2004 paper by Dutch virologist Thijs Kuiken, cat-to-cat transmission is possible and could provide an "opportunity for this avian flu to adapt to mammals".
Professor Peter Openshaw, head of respiratory infections at London’s Imperial College, says intimate contact between cats and their owners heightens the risk of transfer and potentially lethal mutation. He also says the transfer of bird flu from birds to cats increases the risk of the virus strain mutating into one that passes more readily between humans – a scenario that scientists fear will create a devastating global pandemic.
However, the H5N1 strain does not jump easily to other species – and this applies to cats as well. The World Health Organization says there is no present evidence that domestic cats play a role in the transmission cycle of H5N1 viruses. To date, no human case has been linked to exposure to a diseased cat. And the head of the British Veterinary Association, Frieda Scott-Park, says that we should all hang on to the thought that current strains of the virus are "really inefficient" at infecting non-bird species.
Whatever the actual risks involved, these developments have started to worry pet owners, and specifically cat owners, across the globe. Unlike in the United States, in Europe nearly all cats are "outdoor" cats, and it is less practical to restrict their movements. French Prime Minister Dominique de Villepin has urged cat owners not to let their pets stray into areas affected by bird flu.