British scientists have used CRISPR-Cas9, a powerful gene-editing tool, to restrict - but not completely block - the bird flu virus from infecting chickens.
Professor Devi Sridhar, of Edinburgh University, said there are signals of a pattern emerging in avian flu s mutations, which means it could take off among humans at some point .
Rhian Sula, a general manager for the charity in Pembrokeshire, said it had deployed staff to warn visitors about the risks. Touching an infected bird is a known route of transmission.
The Department for Environment, Food and Rural Affairs said that while the risk of cats catching the disease is very low, people should still take precautions to limit exposure to their pets.