World First on Bird Flu: A Sheep Tests Positive

We can add one more animal to the list of those known to have contracted bird flu: sheep. Health officials in Britain say the virus turned up in a single sheep on a farm in an undisclosed location, reports the BBC. Avian flu, aka H5N1, had previously been reported in a wide range of animals beyond birds, including cats, cows, pigs, foxes, and humans, but this appears to be the first time for a sheep anywhere in the world, notes the New York Times. The best guess is that the sheep, which was euthanized after testing positive, came into contact with infected poultry or their droppings.

"In this instance sheep and poultry have mixed on the same farm, resulting in the transmission of avian influenza," said Phil Stocker of Britain's National Sheep Association, adding that the development may lead to new farming practices to keep animals better separated. Health officials continue to emphasize that it remains relatively difficult for the virus to spread to people, notes Scientific American. But the more it jumps and mutates, the more that risk can grow. (More bird flu stories.)