A pandemic is not inevitable, scientists say. But the outbreak has passed worrisome milestones in recent weeks, including cattle that may have been reinfected.

The United States has reported its first outbreak of H5N9 bird flu in poultry on a duck farm in California, the World Organisation for Animal Health (WOAH) said on Monday.

Following an outbreak of bird flu at a Shropshire farm, the entire county has been put into an Avian Influenza Prevention Zone (AIPZ). This means anyone who has birds in Shropshire must house their animals. This applies whether or not you have just one or two chickens in a back garden right up to large commercial flocks.

The H5N1 Avian influenza is decimating bird populations around the world. More than 136 million birds have been affected in the US since the disease arrived in 2022. More than 5 million egg-laying chickens died in the first 16 days of 2025.