Department of Agriculture, Trade and Consumer Protection

Disease Basics​​

Avian influenza (AI)​, or bird flu, is a virus​ that infects domestic poultry, such as chickens, turkeys, pheasants, quail, ducks, geese, and wild birds, pa​rticularly water​fowl. Direct contact with infected birds, contaminated objects or equipment, and aerosol (short distances) can spread the ​virus, which is found in feces, saliva, and respiratory secretions.

AI viruses are divided into two groups — highly pathogenic (HPAI) and low pathogenic (LPAI) — based on the ability of the virus to produce disease and the severity of the illness it can cause. HPAI spreads rapidly and has a high death rate in birds. LPAI causes minor illness and occurs naturally in migratory waterfowl. 

In addition to wild birds and domestic poultry, HPAI viruses have been detected in some mammals, including livestock.

There are many strains of AI, many of ​which show little or no visible signs of illness and po​se no threat to public health. Each year new strains of AI may appear throughout the world.​​

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HPAI in Cattle 

​Prevention

Biosecurity is a set of practices designed to reduce the risk of spreading disease from sick birds to healthy ones. The Wisconsin Department of Agriculture, Trade and Consumer Protection recommends adding these practices to your routine:

• Restrict access to your property, and keep your birds away from other birds.
  
• Keep a designated pair of shoes to wear around your birds, wash clothing after visiting your birds, and use disinfectants correctly.
  
• Clean and disinfect cages, poultry equipment, and car tires after visiting a farm store, poultry swap, or other location where birds are present.
  
• Keep new birds separate from your flock for 30 days; quarantine returning birds from the rest of your flock after visiting a poultry swap, exhibition, or other event.
  
• Do not share equipment or supplies with others. If you must, disinfect it first.
  
• ​Wash hands before and after bird handling.​
  

Clinical Signs of Illness

Many birds with LPAI may not show signs of illness. Poultry affected by any type of AI can show many symptoms, including one or more of the following:

• Decreased food consumption, huddling, depression, closed eyes
  
• Respiratory signs, such as coughing and sneezing
• Decreased egg production, watery greenis​h diarrhea, excessive thirst
  
• Swollen wattles and combs​