Protect Your Poultry From

AVIAN INFLUENZA
What Is Avian Influenza?

Avian influenza, or “bird flu,” is a 

respiratory disease of birds caused 

by influenza A viruses. Wild birds, 

such as ducks, gulls, and shorebirds, 

can carry and spread these viruses 

but may show no signs of illness. 

However, avian influenza can kill 

domestic poultry (such as chickens, 

turkeys, ducks, and geese). 

Avian influenza viruses are 

classified based on a combination 

of two groups of proteins: the 

hemagglutinin or “H” proteins, of 

which there are 16 (H1–H16), and 

neuraminidase or “N” proteins, of 

which there are 9 (N1–N9). These 

viruses are further categorized as 

either low or high pathogenicity, 

indicating their ability to produce 

disease in poultry. 

Low pathogenicity avian influenza 

is common in wild birds in the United 

States and around the world. In most 

cases, it causes few or no signs of 

infection. However, some strains can 

become highly pathogenic in poultry. 

Highly pathogenic avian influenza 

is extremely contagious and deadly 

to domestic poultry. If we find it in 

the United States, we must quickly 

eradicate the disease to protect our 

Nation’s flocks and economy.

PROTECT YOUR POULTRY FROM AVIAN INFLUENZA

AVIAN INFLUENZA,

OR “BIRD FLU,”

IS A RESPIRATORY

DISEASE OF BIRDS

CAUSED BY

INFLUENZA A VIRUSES.
Avian influenza spreads quickly by direct, birdto-bird contact. It can also spread indirectly, 

such as when birds come in contact with 

contaminated surfaces or materials. Migratory 

waterfowl (including wild ducks and geese); 

smuggled poultry and poultry products; and the 

movement of poultry, poultry equipment, and 

HOW DOES BIRD FLU SPREAD?

people are potential sources for introducing 

the disease to domestic birds. Avian influenza 

viruses can be moved in manure; on egg 

flats, crates, or other farming materials and 

equipment; and even by people who may 

have inadvertently picked the virus up on their 

clothing, shoes, or hands.
BIOSECURITY IS KEY TO PROTECTING YOUR FLOCK

Biosecurity signage on a farm

Fencing your bird area can help keep your flock safe from predators and from contact with other birds that could spread disease.

Everyone who owns or works with 

poultry—whether you’re part of a 

large commercial operation or raise 

birds as a hobby—needs to know the 

right steps to keep avian influenza 

from entering the premises. Making 

biosecurity an “every day, every 

time” practice is the best way to 

protect your birds. Even if you’re 

already familiar with biosecurity, 

it’s always good to double-check 

your procedures. You are the best 

protection your birds have! 

It takes just one contact with this 

virus to sicken or kill your birds. In a 

single day, the avian influenza virus 

can multiply and infect every bird on 

your premises. USDA file photo
Complete the self-assessment 

of biosecurity practices 

available at uspoultry.org/

programs/poultry-health/

biosecurity (click on “USDA 

Biosecurity Self-Assessment”). 

The U.S. Department of 

Agriculture (USDA) partnered 

with States and industry to 

develop this assessment as an 

aid for all commercial poultry 

owners in understanding and 

putting in place enhanced 

biosecurity measures. You 

can also contact your industry 

organization for more resources. 

ATTENTION 

COMMERCIAL 

PRODUCERS!

Allowing your flock to come 

in contact with wild birds could 

put it at risk for infectious poultry 

diseases.

Protect your birds with a few simple steps:

Keep Germs Away

Disinfect shoes, 

clothes, hands, 

egg trays or flats, crates, 

vehicles, and tires. Avoid 

exposing cleaned and 

disinfected equipment and 

tools to wild birds.

Wash hands and scrub boots 

before and after entering a 

poultry area. Wear disposable 

boot covers and coveralls 

if possible.

Isolate any birds returning 

from shows for 30 days to 

observe for signs of illness 

before placing them with the 

rest of your flock.

Buy birds from reputable 

sources so you know you are 

getting healthy birds.

Limit Visitors

Restrict traffic 

onto and off of 

your property.

Prevent visitors from having 

contact with your flock, and 

avoid visits to other poultry 

farms or with bird owners.

If you or others must visit (such 

as service providers), make sure 

to wash hands and scrub boots 

before entering the bird area. 

Use and offer disposable boot 

covers and coveralls whenever 

you can.

Avoid Wild Birds 

and Pests

Keep wild birds and 

rodents out of poultry houses 

and coops.

Don’t let your poultry have 

contact with migratory waterfowl 

or other wild birds. These 

birds can introduce germs and 

diseases to your flock.

Secure feed bins and 

water to prevent wildlife 

contamination.

Have a Plan

If you own a 

commercial farm, 

you should have a sitespecific biosecurity plan 

in place. 

Make sure that anyone 

who enters the poultry area 

or has contact with your 

birds knows and follows your 

biosecurity rules.

For backyard bird owners 

and hobbyists, we encourage 

you to have a written biosecurity 

plan, too. It’s one of the best 

ways you can defend your birds 

from disease.
Early detection is vital to prevent the spread of HPAI. Here’s what to look for:

WHAT ARE THE SIGNS OF AVIAN INFLUENZA?

• Sudden death without any prior symptoms of illness 

• Lack of energy and appetite

• A drop in egg production or soft-shelled, misshapen eggs

• Swelling of the eyelids, comb, wattles, and shanks

• Purple discoloration of the wattles, comb, and legs

• Gasping for air (difficulty breathing)

• Nasal discharge, coughing, sneezing

• Twisting of the head and neck (torticollis) 

• Stumbling or falling down

• Diarrhea

Swelling of the tissue around the eyes and 

purple discoloration of the comb and wattles

Complete paralysis

Twisting of the head and neck

Swelling around the eyes and twisting of the neck
ALERT! 

While an occasional 

unexplained bird death is 

normal, a large percentage 

of dead or dying birds in 

your flock is not normal. 

If there’s no obvious 

cause (such as predators, 

weather issues, or other 

external factors), report 

the deaths to animal health 

officials immediately.

ALWAYS REPORT 

SICK BIRDS

If you see these signs, 

take action right away! 

Contact your agricultural 

extension office/agent, 

local veterinarian, local 

animal health diagnostic 

laboratory, or the State 

veterinarian, or call USDA 

toll free at: 

1-866-536-7593
LEARN MORE

USDA has free resources online for anyone who owns or handles 

live poultry. This includes a series of checklists to help you practice good 

biosecurity consistently. Download the checklists and more at 

www.aphis.usda.gov/animalhealth/defendtheflock

(click on “Resource Center”). 

And don’t forget—report sick birds right away by calling

1-866-536-7593.

This publication supersedes Program Aid No. 2212, “Protect Your Birds From Avian Influenza,” which was published in March 2017.

The cover image is by NikonShutterman, Getty Images. The biosecurity signage image and the photo of several chickens 

next to a duck are by USDA, R. Anson Eaglin. All other images in this brochure are also by USDA employees.

USDA is an equal opportunity provider, employer, and lender. 

Program Aid No. 2252 • Issued October 2019 • Slightly revised February 2022