Avian Influenza and backyard chickens

How weird did 2022 get? There had not been very much activity in the world of bird flu over the last few years and suddenly it was being detected in wild bird populations. Just to recap really quickly: ducks shot by hunters in South Carolina have tested positive for the Asian strain of H5N1 avian influenza. 

Chicken with mask on

Wild birds can easily transmit this disease to pet chickens, ducks and other poultry so out of an abundance of caution, many chicken keepers in the area have completely locked down their birds. Since that first duck tested positive, 2 more then tested positive, one in close proximity to the first and the other in North Carolina. Read more about those ducks here.

*sigh* Anyone else feel like 'here we go again'? At this point nobody is sure whether this is just a tiny issue that will resolve itself or if we're going to be facing a do-over of the 2015 turkey industry slaughter. Time will tell. 

Until we see exactly where we're going with this though, lets talk about some of the things we learned from past experiences with avian influenza and how to keep our flocks of chickens and other poultry safe. Lets start with the different types and behaviors of the virus. 

What is Avian Influenza?

As the name suggests, avian influenza refers to the infection caused by avian (bird) influenza (flu) viruses. These viruses are commonly found in intestines of wild birds and these birds can carry the viruses without getting sick. Like the ducks mentioned above who appeared healthy.

However the viruses can be pathogenic to domesticated birds like chickens, ducks and turkeys. Domesticated birds become infected through exposure to infected wild birds or through surfaces contaminated by nasal secretions, saliva and feces of the infected birds.

These viruses are classified as Low Pathogenicity and High Pathogenicity. 

Most strains of Avian Influenza come under Low Pathogenicity Avian Influenza (LPAI) Group and produce mild symptoms in the infected birds. Common symptoms are ruffled feathers, decreased appetite, decreased egg production, sneezing and coughing. Many times LPAI may go undetected.

High Pathogenicity Avian Influenza (HPAI) has more severe symptoms which include sudden death, loss of energy and appetite, decreased egg production, respiratory problems, facial oedema (swelling), poorly formed eggs and diarrhea. HPAI can reach a mortality rate of nearly 100%.

person in lab coat and mask with word Bird Flu in red

Let me repeat that. 

Symptoms of avian influenza in chickens

Symptoms may include: ruffled feathers, decreased appetite, decreased egg production, sneezing & coughing, sudden death, loss of energy, respiratory problems, facial oedema (swelling), poorly formed eggs and diarrhea.

Unfortunately these are also symptoms of several other poultry diseases, so it can be hard to determine if it really is AI without a test through the dept of agriculture. 

For instance if I had a chicken who was lethargic, ruffled feathers, runny poop and not eating much I'd probably suspect coccidiosis before I'd jump to bird flu. Half of the other symptoms sounds like a plain old respiratory infection.

Which is why it's so important to stay informed on the movement of this disease and keep aware of whether it's moving through your community or not. More on that below. Back to this exact virus...

What Is H5N1 strain of Bird Flu?

All flu viruses are classified as type A, B or C depending on their structural arrangement. 

  • Type A is responsible for lethal pandemics and is found in both animals and humans. 
  • Type B causes local outbreaks of flu. 
  • Type C is the most stable of the three and infected people show only mild symptoms of flu. 
  • Type B and C are usually found only in humans. 
  • Type B and C are more stable than type A and are not classified according to their subtypes.

Influenza viruses of type A are divided into subtypes and the naming is done on the basis of two proteins (antigens) found on their surface - Hemagglutinin (HA) and Neuraminidase (NA). Sixteen types of HA and nine types of NA exist. Thus a total 144 combinations are possible.

Thus H5N1 is a type A virus and gets its name from HA 5 protein and NA 1 protein present on its surface.

Type A viruses are further classified into strains. These strains can continuously evolve into different strains. Their ability to exchange genetic material with other viruses and create new influenza viruses makes them unpredictable and difficult to fight with. Humans have to develop new immunity (antibodies) every time new strains are created.

Small changes known as "Antigen Drift" are continuously creating new strains of viruses. However when genetic material from Type A viruses from different species - say a bird and a human, comes together and merges, an entirely new strain is created. This is known as "Antigen Shift" Humans have no immunity to such a strain and the strain can spread rapidly.

From birds to chickens

Domesticated poultry may get the virus from contact with contaminated surfaces too. Like if a wild bird poops on your porch and your chicken walks through it. Remember it's also spread through respiratory droplets which you wouldn't be able to see easily...so the virus could be lurking anywhere an infected wild bird has been recently. 

Once a virus infects domesticated birds, it can move quickly among the whole flock. Humans come in contact with infected birds or contaminated surfaces and can pick up the virus. For instance when you're touching the waterer to empty and refill it.

Clearly we want to prevent any of this happening so our logical first step is to control the disease from spreading among domestic poultry. To do that we need to keep our pet chickens from having contact with any wild birds.

Biosecurity sign on farm gate

How to keep chickens safe from avian influenza

We've all learned a lot about quarantine procedures over the last 2 years and you're going to need all that information right now. Your goal as a backyard chicken keeper is to keep all wild birds and their bodily fluids away from your domestic poultry.

Do not allow free ranging if H5N1 has been detected in your area. Only allow chickens outside in a solid covered run. Net or poultry wire covers will not do because a wild bird can perch on them and will poop which will fall inside the run. They must have a solid roof above the run. 

If fencing is used on the sides of the run it must have holes that are too small for wild birds to get through. If you happen to have large holes in your fencing, you can zip tie bird netting to it temporarily to keep small birds out.

In Cooped up chickens. Do they have to come out? I talk about chickens not needing to be outside their coop every day, especially in situations like these. 

Make sure all ventilation holes in the roof line of the coop are covered with poultry wire to keep wild birds from coming inside the coop looking for food. Do not leave doors and windows open unless they are protected with screens.

Quit feeding wild bird populations. I talk about how to safely feed wild birds in How to feed the wild birds but protect your chickens. I discuss feeding birds far away from where your poultry are. Unfortunately that's not going to be enough right now, and you'll want to cease feeding wild birds completely.

If you live by a pond, lake or stream and you have ducks, you'll need to keep your ducks out of the water. You wouldn't want them to come in contact with feces left behind by wild ducks. If you can switch to a kiddie pool inside their covered run for now, it should keep them happy while staying safe. 

Be very aware of where you walk on your way to the coop. When the department of agriculture was here for my NPIP inspection they required pans of water outside the coops to clean shoes before going in. You would spray a disinfectant on your boots, scrub with a brush then step in the water to rinse it all off.

Yes, it's a lot of extra work. It's worth it if it keeps your flock safe. Last time this happened entire flocks were put down! It's definitely worth the extra steps to keep yours safe!

How Is The Virus Transmitted To Humans From Birds?

Usually Avian Influenza viruses do not infect humans. Migratory birds act as carriers of these viruses and do not get affected by them. (like the healthy ducks that started this whole episode) These birds then come in contact with domesticated birds such as chickens and turkeys and spread the infection to them. 

The next step is to prevent the disease from getting passed on to humans. People who come in close contact with poultry are advised to keep a close watch on the health of birds, notify any sort of sickness in birds to the department of agriculture and avoid direct contact with sick birds, in all cases. 

Ducks have become a reservoir for the virus and may not exhibit signs of sickness even if they are carrying the virus. Wear disposable nitrile gloves when tending to your ducks. If ducks and chickens are kept separately, tend to the chickens first. 

You'll want to wear an N95 mask when tending to your animals as the virus can become airborne. Wash hands and change clothes after exiting the coop.

You'll also want to stay in touch with the local poultry community. If someone in the area is experiencing a problem with their chickens you want to know about it! I find local groups (like on Facebook) very helpful for keeping informed. 

Keep an eye on your local news also. If any wild or domestic birds have tested positive for H5N1, it will probably be in the news shortly after.

A person infected by bird flu may have all symptoms of common flu like fever, persistent cough, sore throat and body ache. Bird flu and ordinary human flu have almost the same symptoms. Unfortunately this sounds a lot like that other thing going around, so if you do get sick with those symptoms and test negative for that other virus, inform your medical professional that you have chickens or other backyard poultry. 

I am not in the veterinary or medical field and my information is for informational and entertainment purposes only. Please check out the CDC's page on Avian Influenza in humans for more information. 


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  1. Great information, thank you for taking the time to post.

  2. Keep the information coming enthusiastic reading here in UK.

  3. Thanks for the heads-up! This was very informative and easily understood by a lay person. I save all your posts and use them as references so I appreciate the time you take to produce this newsletter.

    1. Awesome! That is exactly what I was going for...some of the stuff I was reading while doing research made my head spin and I was trying so hard to break it down properly. Glad you enjoyed the post!