Bird flu kills cats in Poland and WHO’s warning. What’s happening?

An unusual number of cats have died across Poland, authorities said. More than half of those tested harbored the strain of bird flu known as H5N1, the World Health Organization said. Of 47 samples tested — including one wild cat in captivity — 29 were positive for the H5N1 flu.

This marks the first report of “high numbers of infected cats over a wide geographical area within a country,” the WHO said in a statement.

The flu strain found in birds could combine with one that is able to circulate in humans, the health agency warned. This could result in a new version that transmits easily enough to spark a pandemic, it said.

What were the symptoms and how serious is it?

Several cats developed severe symptoms including breathing difficulty, bloody diarrhea and neurological problems, the WHO said. However, the general population is at low risk of contamination. The threat for cat owners and vets as “low to moderate”, the agency said.

The cats could have had contact with infected birds or their environments, the WHO said. Some of the cats were outdoor animals while others lived indoors, it noted.

Has there been reported cases in human transmissions?

No human contacts of the infected cats had reported any symptoms, WHO said, adding that the surveillance period for those individuals is now complete.