Wisconsin agriculture officials have confirmed a highly contagious bird flu outbreak in a backyard poultry flock in Rusk County, triggering the euthanasia of every bird on the affected property. The finding has also prompted renewed warnings for livestock owners to strengthen safeguards around their animals.

The Wisconsin Department of Agriculture, Trade and Consumer Protection confirmed the case Thursday. Testing identified highly pathogenic avian influenza, commonly known as HPAI, among birds in the backyard flock.

Officials did not specify how the flock became infected. The department said all birds on the property were euthanized and will not enter the food system.

The response was intended to prevent the disease from spreading beyond the affected property. Depopulation removes infected birds from the premises while ensuring that they cannot be distributed for food.

HPAI is a highly contagious virus that is often fatal to domestic poultry, according to the department. It has circulated among wild and domestic birds across North America since December 2021.

The disease is caused by influenza type A viruses. Its severity can vary depending on the particular strain involved and the species affected by the infection.

The virus can spread when animals come into contact with infected birds, wild birds or bird droppings. That range of possible exposure creates risks for backyard flocks as well as other animals kept near potentially contaminated areas.

Contaminated equipment can also carry the virus, according to Wisconsin agriculture officials. Clothing worn by people working with animals may become another route of transmission if proper cleaning and disinfection steps are not followed.

The department did not identify which possible route led to the Rusk County outbreak. Without a specified source, officials focused their public guidance on precautions that can limit several recognized forms of transmission.

When HPAI is confirmed in a backyard poultry flock, authorities may establish a surveillance zone extending 10 kilometers from the affected location. Such a zone allows officials to monitor the surrounding area after an infection has been detected.

Poultry premises within the surrounding area would not face movement restrictions, according to the department. The possible surveillance measure therefore does not automatically prevent nearby owners from moving their birds or related materials.

DATCP urged livestock owners to wash their hands as part of their protective routine. Officials also recommended disinfecting equipment that could carry contaminated material between animals, enclosures or properties.

Restricting access to animals is another precaution recommended by the department. Limiting contact can reduce opportunities for contaminated clothing, equipment or other materials to reach a flock or herd.

Officials also advised owners to separate newly added animals for at least 30 days. That precaution provides a period in which new additions are kept apart from an existing flock or herd.

The Rusk County case places fresh attention on a disease that has continued circulating among birds for years. For Wisconsin livestock owners, the department’s warning centers on controlled access, clean equipment, careful handwashing and separation of new animals.

Although all birds on the affected property were euthanized, officials said they will not enter the food system. The department’s response now combines removal of the infected flock with precautions aimed at protecting other animals from exposure.