U.K. detects first case of bird flu in a sheep, stoking fears of spread

Mammals worldwide, including sheep, have died from H5N1 bird flu, but public risk remains low.

Bird flu has been detected in a sheep in northern England, the first known case of its kind in the world, Britain's Government said, adding to the growing list of mammals infected by the disease and fuelling fears of a pandemic.

Many different mammals have died of the H5N1 bird flu virus across the globe including bears, cats, dairy cows, dogs, dolphins, seals and tigers.

"The case was identified following routine surveillance of farmed livestock on premises in Yorkshire where highly pathogenic avian influenza (H5N1) had been confirmed in other captive birds," Britain's Government said in a statement.

There have been cases among humans which have ranged in severity from no symptoms to, in rare cases, death. But there has not yet been any confirmed transmission between humans.

The sheep that tested positive was a ewe with signs of mastitis, an inflammation of breast tissue, and no other clinical signs, the statement from the British government's Department for Environment, Food and Rural Affairs, and the Animal and Plant Health Agency said.

Ed Hutchinson, professor of molecular and cellular virology, MRC-University of Glasgow Centre for Virus Research, said the fact that the sheep's milk also tested positive suggested parallels with the ongoing H5N1 outbreak among dairy cows in the United States.

Bird flu has spread among U.S. dairy cattle since March 2024.