Avian Influenza

Last Updated: March 25, 2025

What is Avian Influenza?

Avian influenza viruses, commonly called “bird flu,” are influenza type A viruses that naturally occur in bird populations. The viruses are transmitted from bird to bird through fecal droppings, saliva, and nasal discharges. Avian influenza viruses can infect poultry (such as chickens, turkeys, pheasants, quail, domestic ducks, geese, and guinea fowl) and wild birds (especially waterfowl).

How Does Avian Influenza Spread?

Birds along the North American flyways can intermingle with infected birds. Positive tests in wild waterfowl can occur, and waterfowl can be infected and show no signs of illness. There is a risk for transfer from wild birds into domestic poultry and vice versa, resulting in further spread. Avian Influenza can spread from animal to animal and can affect species other than poultry. HPAI is zoonotic, meaning it can be spread to humans.

To see all wild mammal species that have been affected with HPAI, visit the USDA-APHIS website. Find information about the cases of HPAI detected in U.S. livestock at aphis.usda.gov.

Low pathogenicity avian influenza (LPAI) viruses typically cause little or no clinical signs in infected poultry. The LPAI virus is excreted through infected birds’ feces and respiratory secretions. It spreads primarily through direct contact between healthy and infected birds. It can also be spread through indirect contact with contaminated equipment and materials. Low pathogenicity avian influenza (LPAI) virus strains occur naturally in wild migratory waterfowl and shorebirds without causing illness.

Highly Pathogenic Avian Influenza (HPAI) is a serious disease and requires rapid response because it is highly contagious and often fatal to chickens. The goal is to quickly contain and eradicate the disease, protecting our poultry industry, and in turn, the American consumer.

Due to the Avian Influenza response, please submit a permit request form in order to move poultry.

HPAI in Dairy

• The U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) has confirmed the detection of highly pathogenic avian influenza (HPAI) in U.S. dairy herds. Learn more on how USDA is managing the evolving situation at https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/livestock.
• MDA Milk Testing Guidance for Missouri Dairy Producers
• Missouri State Fair Dairy Exhibition Protocols
• HPAI in Livestock Flyer

Frequently Asked Questions

Is chicken and other poultry safe to eat?

Chicken and other poultry products are safe to eat if they are properly handled and cooked. The affected birds have been quarantined and will not affect the food supply.

The U.S. Centers for Disease Control and Prevention (CDC) considers the risk to the general public from these infections in wild birds, backyard flocks, and commercial poultry, to be low.

Is there reason to be concerned HPAI may spread to mammals more commonly than previously believed?

HPAI has been found in wild birds, poultry flocks, several species of wild mammals, dairy cattle, alpacas and neonatal goats in the United States. A full list can be found here. Many species are susceptible to influenza viruses, including wildlife that often come into direct contact with wild birds. Many of these animals were likely infected after consuming or coming into contact with birds that were infected with HPAI. In the case of the neonatal goats in Minnesota, they were exposed to domestic birds (ducks and chickens) infected with HPAI through shared pasture and a sole water source. However, testing indicates that HPAI transmission between cattle cannot be ruled out.

Have there been any cases of Avian Influenza in Humans?

There have been cases of avian influenza in humans. Nearly each case involved people who worked in close contact with livestock also positive for avian influenza. There has been no spread from person to person. According to the Center for Disease Control, the current public health risk remains low. Learn more at cdc.gov.

What can bird owners do to protect their flocks?

• Avian Influenza flyer
• Register for a federal premises ID number

What are the warning signs?

• Decrease in water or feed consumption
• Respiratory signs, such as coughing and sneezing
• Quietness among the flock
• Decrease in egg production
• Sudden increase of death in your flock