What is avian influenza?

Avian influenza, also known as bird flu, is a highly contagious viral disease affecting chickens and turkeys, but many other birds are also susceptible. Aviary influenza viruses can basically be divided into two groups: low pathogenic (causing mild illness) and highly pathogenic (causing severe illness) influenza viruses. Highly pathogenic aviary influenza viruses (e.g., H5N8) can lead to high animal losses in farm poultry, such as chickens or turkeys. Low pathogenic influenza viruses, on the other hand, often cause only minor or no symptoms of disease, as these viruses lack the properties to cause severe illness. Only infection with highly pathogenic avian influenza viruses is referred to as avian influenza.

Avian influenza – mandatory housing requirement lifted

The state capital of Wiesbaden is completely lifting the mandatory housing order for poultry that has been in effect since last November. This already applied to poultry farms with fewer than 50 animals in December 2025. Thanks to the new general ruling of January 17, 2026, larger farms will also be able to let their poultry out into the open again starting on Sunday. Wiesbaden is following other districts in Hesse in this regard, as the outbreak has also subsided in Wiesbaden. 

However, biosecurity measures must still be observed, as these are an effective tool for reducing the risk of pathogen introduction.

For poultry farmers, this means that they must continue to protect their stock by taking sensible measures such as wearing protective clothing, controlling rodents, and regularly cleaning and disinfecting equipment.

Dead wild birds and waterfowl should continue to be reported to the Office for Veterinary Affairs. Outside office hours, please contact the fire department control center.