The British government has confirmed the first known case of bird flu in a sheep, marking a global first and raising concerns about the increasing spread of the H5N1 virus among mammals.
According to a statement from the UK’s Department for Environment, Food and Rural Affairs (DEFRA) and the Animal and Plant Health Agency, the case was identified during routine surveillance of farmed livestock in Yorkshire.
The location had previously reported highly pathogenic avian influenza (H5N1) in captive birds.
“The case was identified following routine surveillance of farmed livestock on a premises in Yorkshire where highly pathogenic avian influenza (H5N1) had been confirmed in other captive birds,” the statement read.
The spread of bird flu among mammals has been an ongoing concern, with infections recorded in a wide range of animals, including bears, cats, dairy cows, dogs, dolphins, seals, and tigers. While there have been human cases—ranging from asymptomatic infections to fatalities—there is no confirmed human-to-human transmission at this time.
The infected sheep, a ewe, exhibited signs of mastitis, an inflammation of breast tissue, but showed no other clinical symptoms. Notably, its milk tested positive for the virus, drawing comparisons to the recent H5N1 outbreak among dairy cows in the United States.
Ed Hutchinson, a professor of molecular and cellular virology at the MRC-University of Glasgow Centre for Virus Research, highlighted this similarity, stating, “The fact that the sheep’s milk also tested positive suggested parallels with the ongoing H5N1 outbreak among dairy cows in the United States.”
However, he reassured that “at the moment there was no evidence of ongoing transmission from the sheep and the case appeared to have been contained.”
In response to these developments, the UK government has enhanced surveillance measures for livestock on farms where bird flu has been detected in captive birds, particularly in light of recent outbreaks in U.S. dairy cattle.
