• More bird flu found in Wisconsin commercial poultry flocks

(AP Photo/Charlie Neibergall, File)

HEALTH

BY Rachel Ryan and Jason Fechner Wisconsin

UPDATED 2:53 PM ET Mar. 06, 2026 PUBLISHED 9:47 AM ET Mar. 06, 2026

WISCONSIN — Bird flu has been confirmed in two separate commercial poultry flocks in the state, according to the Department of Agriculture, Trade and Consumer Protection.

One of the flocks is in Jefferson County and contains around 1.6 million birds. The other is in Walworth County, with a flock of nearly 1.5 million.

What You Need To Know

The third and fourth cases of bird flu have been confirmed in WisconsinOne of the flocks is in Jefferson County and contains around 1.6 million birds. The other is in Walworth County, with a flock of nearly 1.5 million
This is already the second case in a commercial flock in Jefferson County this year, but the first for Walworth County
In both new confirmations, DATCP said flocks have been quarantined and birds on the property were depopulated to prevent spread

This is already the second case in a commercial flock in Jefferson County this year, but the first for Walworth County. The other flock in Jefferson County with bird flu consisted of 1.2 million poultry.

Overall, there have now been four cases of bird flu in either commercial or backyard poultry flocks this year. All confirmed cases in 2026 have been within the last couple of weeks.

In both new confirmations, DATCP said flocks have been quarantined and birds on the property were depopulated to prevent spread.

The highly contagious sickness has been circulating in North America since Dec. 2021. It’s often fatal to domestic poultry and is caused by influenza type A viruses, according to DATCP. It can be spread when coming in contact with an infected bird or “commingling with wild birds or their droppings, equipment, or clothing worn by anyone working with the animals.”

Here are some symptoms to watch out for, according to DATCP:

• Sudden death without clinical signs
• Lack of energy or appetite
• Decrease in egg production; soft, misshapen eggs
• Purple discoloration of wattles, comb and legs
• Difficulty breathing
• Runny nose, coughing, sneezing
• Stumbling or falling down
• Diarrhea

Last year, there were five cases in the state, two of which were in commercial flocks and three in backyard flocks. 

More bird flu found in Wisconsin commercial poultry flocks

Also see:

Bird flu cases confirmed in Jefferson, Walworth counties; millions of birds to be culled | Exposing the Big Game

• Chad Thompson
• Mar 6, 2026 Updated 4 hrs ago
• Bird flu cases confirmed in Jefferson, Walworth counties; millions of birds to be culled | News | wkow.com

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MADISON (WKOW) — Bird flu is impacting two commercial poultry flocks in southern Wisconsin. 

The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) confirmed cases of highly pathogenic avian influenza (HPAI) in Jefferson and Walworth counties. The cases were identified on Wednesday.

DATCP’s data page shows 1,621,847 birds affected in a Jefferson County commercial poultry flock. It shows 1,493,596 birds affected in a commercial poultry flock in Walworth County.

The discovery has prompted immediate action to prevent the spread of the virus.

A separate case involving 1,219,988 birds was reported in a commercial flock in Jefferson County in late February.

DATCP and the U.S. Department of Agriculture (USDA) are working together on a joint incident response. The affected premises have been quarantined, and the birds will be culled to stop the disease from spreading, according to a press release. Officials assure that birds from the flock will not enter the food system.

The H5N1 HPAI virus, which has been present in North America since December 2021, is highly contagious and often deadly to domestic poultry. The virus spreads through contact with infected birds or contaminated equipment and clothing.

DATCP is urging all livestock owners to adopt strong biosecurity measures. This includes washing hands, disinfecting equipment, and keeping new flock members separated for at least 30 days. Poultry owners are advised to keep birds indoors when possible.

A control area is established within a 10-kilometer radius around the infected site, restricting poultry movement. Poultry owners can use DATCP’s mapping tool to check if they are in an active control area.

Despite the outbreak, the risk to the general public remains low. Wisconsin Department of Health Services and Walworth County Public Health are monitoring farm workers for symptoms.

For more information on prevention and updates, visit the DATCP’s HPAI in Poultry webpage.