The virus spreads through direct bird-to-bird contact or indirectly when virus is on clothing, footwear, vehicles, rodents, insects, feed, water, feathers, etc. Birds release or shed the virus in bodily fluids such as respiratory droplets, mucus, saliva, and feces.

At this time, the risk to the general public's health from the current H5 bird flu virus is low.  Some people may have job-related (animal control, veterinary clinic, poultry processing plants, etc.) or recreational exposures that put them at higher risk of infection.  People who work with or handle sick birds may consider using additional personal protective equipment (PPE). For more information about protective actions that should be taken when handling birds potentially infected with avian influenza viruses, review CDC prevention strategies.

Monitoring for human infection and person-to-person spread is extremely important for public health because of the possibility that bird flu viruses could change and gain the ability to spread easily between people.

H5 bird flu is primarily a disease of poultry (chicken, turkeys) and may cause significant loss in backyard and commercial flocks. In wild birds, the infection may cause mild to severe illness depending on the species affected.

H5 bird flu has been reported to affect other types of animals including those that share environments with infected birds or that scavenge or eat infected birds.  Globally and in the US, other animals infected with H5 bird flu include skunks, foxes, mountain lions, bears, raccoons, opossums, bobcats, a coyote, harbor seals, a river otter, baby goats, and a bottlenose dolphin.  A number of these animals were found dead in groups which prompted investigation and testing by various agencies. For more information about H5 bird flu in mammals, see surveillance data from USDA.

Domestic pets have also been found to be positive for H5 bird flu and can die from the infection.  In April 2023, a dog in Ontario, Canada tested positive for H5 bird flu and died after chewing on a dead goose.  This is the first case reported globally of a dog contracting this strain of the virus.  Three cats in the US (1 in Wyoming in April 2023 and 2 in Nebraska in January 2023) suspected of hunting and eating wild birds tested positive for H5 bird flu.  The 2 cats in Nebraska showed neurologic signs (tremors, seizures, walking in circles) prior to dying.  To prevent infection in pets, they should not have contact with wildlife including wild birds, and not consume raw or uncooked poultry and unpasteurized milk or milk products.

• Sudden death of bird with no clinical symptoms
• Lack of energy
• Loss of appetite
• Swelling of head, comb, eyelid, wattles and hocks
• Discoloration of wattles, combs and legs
• Nasal discharge
• Coughing
• Sneezing
• Neurological signs (incoordination)
• Diarrhea

• No symptoms
• Neurological signs (incoordination, swimming in circles, weak)
• Sudden death

Please refer to these resources:

• USDA: Defend the Flock
• USDA: Protect Your Poultry from Avian Influenza