Disclaimer:
I do not have a degree in epidemiology (although I do hold a master’s in applied health sciences). However, I work closely with a community of keepers that include commercial poultry veterinarians who provide up to date and science backed information for best practice poultry keeping. I am also in frequent contact with my NPIP tester who sends me articles and informationals on flock protection. This is the aggregate information I have put together on the subject of how we, as backyard flock keepers, can keep our birds safe from not only Avian Influenza but also other diseases that are brought on by wild birds or poor biosecurity. While no guarantee of being 100% safe can be made, the steps outlined below significantly reduces your flock’s risk.
If you’d like to track the current Avian Influenza outbreaks in the US:
APHIS Wild bird detections database: https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/wild-birds
Commercial and backyard flock detection database: https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/commercial-backyard-flocks
Mammalian detection database: https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/mammals
What is Avian Influenza?
Avian Influenza is a group of Influenza A viruses that affect mostly birds but that can also infect humans (zoonotic) and other mammals (and some strains have done so in the past). They can be transmitted between avian species, and individuals much like how the human flu transmits between people–it is believed that the current variant of interest (HPAI H5N1 strain) can only be transmitted from animal to human, and have not yet mutated in a way where it could transmit between humans. H5N1, H7N9, H5N6, H9N2, H10N7 are just some of the variants and subclades of Avian Influenza.
Avian influenza includes both low pathogenic (LPAI) and high pathogenic (HPAI) variants that cause devastating losses in both commercial and backyard flocks. Avian survivors can be chronic carriers, making complete eradication difficult. Wild bird species, most often waterfowl, are considered its natural reservoir with carriers that spread it during migratory seasons.
Onset for HPAI in chicken flocks which have little to no immunity (and not HPAI’s natural host species) is rapid, often wiping out small backyard flocks in 48 hours or less. Backyard poultry keepers report that they wake up one morning to a majority of their flock dead with the rest dying. My NPIP (National Poultry Improvement Plan) tester told me of a case he worked on, where by the time he arrived to a small hobby keepers home, most were dead and the few that were alive were gasping their last breaths. It was devastating for the owner because they were show birds and his pride and joy.
For commercial production facilities, such as the ones you may have seen in the news (and was the case for a friend of mine who used to work in a commercial layer facility), employees usually walk in to thousands of dead birds which prompts immediate testing and swift euthanasia/culling once confirmed to be HPAI to ensure containment and proper disposal–because of the fact that it can jump to other species, making sure no products from the affected animals enter the food supply is top priority.
Due to its lipid make-up, Avian Influenza has remarkable tolerance to cold and it is hypothesized to be able to be stored indefinitely at very low temperatures and therefore would be a considerable risk as it makes its way through the food supply system. A big cat sanctuary lost more than half (20) of their big cats to Avian Influenza from what they assume may have been contaminated meat.
There is currently no cure for Avian Influenza, and antibiotics do not work because it is viral in origin and not bacterial. It is of great concern due to the speed of onset and the mortality rate of both commercially important birds, and mammals including humans (up to 50%)–the goal is to prevent it from mutating to pass from person to person.
Several animal influenza to human epidemics have already happened actually–the Spanish Flu is thought to have possibly been originally a bird flu, the 2009 Swine Flu, and the 1957 Asian Flu which was a bird flu just to name a few. It really is probability and luck and there are things that can increase the probability–so the jump to epidemic isn’t as rare as it seems and that’s just three among several in the last 150 years. Those viruses eventually burned themselves out (through a combination of vaccination efforts, the majority of the population having been infected already, or evolved to be less deadly), but not before killing hundreds of thousands worldwide.
What are the symptoms of Avian Influenza in Chickens?
Rapid and severe onset of symptoms including: death, lethargy, lack of appetite, convulsions/tremors/paralysis, purple combs/wattles, swollen joints. Usually more than one bird will be affected within the same flock and it is very common for keepers to wake up finding birds dead and dying in quick succession.
How is it spread?
Bird flu (as well as other infectious and fatal chicken diseases, such as mycoplasma, fowl typhoid, fowl cholera, Marek’s disease, Newcastle’s, etc.) is not a spontaneous occurrence. The reason why bird flu occurs in domestic commercial and backyard flocks is due to lapses in biosecurity–chickens are not the natural hosts or reservoir so it is always through an outside source. It is spread through contact with respiratory droplets, fecal matter, and meat.
- Wild birds get into barns because they’re after warmth and feed.
- Weak points in vents and roofs that allow wild animals in.
- Employees lapsed in biosecurity measures (forgot to clean car tires or forgot to bleach dip shoes and tracked infected wild bird poop in.)
- Contaminated feed/water. (Fecal matter from wild birds, or deceased infected birds/small animals, in grain silos or transportation vehicles.)
This is why not every commercial chicken flock has it–some barns are tighter than others with their biosecurity, but people and structures get complacent/weakened over time.
It is the same for backyard flocks.
Why must all the birds be culled? Can’t we separate the healthy ones and just euthanize the sick ones?
The system is currently not designed to do so, and when you touch one animal and touch another during the sorting process, you are inadvertently passing the disease on to even those who may not have been infected. Additionally, in free range barns where there are NO cages, you’re chasing chickens (and boy can they RUN) to grab them while they spread the virus. This is not a clean sorting and the longer it is allowed to go on the more chance of it infecting the workers, the longer it takes to “restart the clock” for the facility that is now on a time crunch to make up for the loss.
It also doesn’t address the fact that some survivors are chronic carriers which greatly increases the chances of it entering the human food supply.
To be clear, the chances of survival for chickens who have contracted Avian Influenza is so minuscule anyway that it makes very little sense from a human and animal health point of view to see if they’ll live as it is a race against the clock for containment.
Is there a vaccine?
Several vaccine candidates for poultry do exist and some are in use, but it’s not yet authorized in the US. Some backyard keepers do immunize their flock against certain diseases (not Avian Influenza) but most of the time it’s more cost effective to just replace dead birds.
Some vaccines are also “leaky”, meaning the vaccinated birds don’t display symptoms and therefore do not die (such as Mareks), but they become chronic shedders and any new birds that come in will need to have been vaccinated or else they will catch it and die. Vaccines have a shelf life too and usually one vial is meant for hundreds of birds. Other issues are also considered–for example, there is a salmonella vaccine but it causes birds to falsely test positive for salmonella… making figuring out which parts of the flock are truly contaminated difficult (because vaccines are not 100%)–although Japan DOES utilize the salmonella vaccine and they are heavy consumers of both chicken and eggs.
Therefore the vaccine/no vaccine debate is a little complicated. I chose not to vaccinate my flock for Mareks because if they catch a particularly virulent strain, I do not wish to be a reservoir (it can be carried by dander, so fomite transfer and wild birds will pass it around) so if they begin dying and test positive for it, I will cull the flock. Avian influenza, if proven not to be a leaky vaccine, I would 100% get for my flock.
A vaccine for humans exist too but is not available to the public–it is often used for employees of commercial operations who come in close contact with poultry. This is good news because it means that it should be relatively easy to ramp up production of it should a human pandemic outbreak occur.
What can I do to protect my flock?
While it all seems very scary, there are a lot of steps you can take to significantly decrease your chances of your flock contracting Avian Influenza as well as other diseases. I have listed them here:
- Do not take in untested, non-NPIP, animals or unsanitized equipment. Rescuing might make you feel good, or you might see a low cost animal that you want for your flock, but you could be unwittingly introducing diseases that can kill more than half your flock, stay in your soil, and survivors become chronic carriers for–Marek’s and Mycoplasma being two of the most common.
- Do not free range: fully covered coop and solid roofed run, with no gaps large enough to allow wild birds or small animals in (19 gauge or thicker hardware cloth, 1/2 inch spacing or smaller provides not only wild critter deterrence but also predator proofing). A large enough overhang to prevent contaminated roof runoff as well as wind driven fecal matter from migrating birds. Make sure there is also good drainage so there won’t be contaminated water runoff making its way into the run.
- Practice biosecurity: Coop and run only shoes (a good pair of waders or rainboots), shoe bleach dip stations (1:10 bleach to water ratio), do not allow visitors near your coop, do not visit property with chickens or waterfowl (and if you must, shower and sanitize your footwear before interacting with your birds, sanitizing the tires of your car.) Wash your hands before and after interacting with your birds or caring for them.
- Mask, goggles, and gloves when cleaning your coop.
- Wild animal deterrents: Keep feed secure, no wild bird or animal feeders or waterers that may attract them to your property, hawk kites to deter birds from coming near your coop and run.
- Wash all produce before giving, do not feed raw meat products, scraps, to your birds.
- Do not eat meat or eggs from sick/dead birds, and do not feed it to your other animals.
These steps are important for not just Avian Influenza but other often fatal diseases that get carried around by wild birds. While a lot of the focus has been on bird flu due to its zoonotic capabilities, there are several other diseases that you would not want your chickens to contract but that they can pick up from other sources.
I am sad my chickens can’t free range! Won’t they be unhappy?
Well here’s the thing, you can make your run as big as you’d like, no one said you have to keep them cramped up–it is recommended that you provide a minimum of 10sqft per standard bird (it can be 4 for bantams) for run space. Then you add enrichment like foraging boxes where you grow plants through wire so they don’t kill the plant but get to enjoy the leafy greens. Lots of perches, sandbaths, hard veggies like cabbages and melons and squashes to poke and kick around. If you look at a parrot in an outside enriched aviary and are okay with it (knowing they will likely die otherwise), you should be okay with chickens in a decent sized enclosure. The coop (connected but separate from the run) should follow guidelines for spacing of about 4sqft per standard bird because too big and they can’t keep each other warm enough in the winter.
Free ranging is the number one cause of deaths in backyard keeper flocks. It is a weird misconception that it’s great for chickens because it leads to:
- Diseases they pick up from wild birds–Avian Influenza is not the only big bad disease out there that can wipe out a flock, it is the only one that freaks people out because it can potentially jump to humans. Mycoplasma, virulent strains of Marek’s, fowl cholera, fowl typhoid, all carried by wild birds (plus a lot of parasites from coming to contact with or eating wild animal fecal matter, or insects, worms, other invertebrates or small animals) can kill 50%+ of a flock. (This is also why the run should be roofed, so wild bird droppings can’t fall in.)
- Hardware disease–Chickens barely have much taste buds, so they like to eat all sorts of junk. When they ingest nails and wires, it punctures their digestive systems and kills them. They also have great appetite for lead paint chips (which then get passed in the eggs or meat we eat), asbestos, styrofoam, and insulation.
- Predators–even if you don’t think you have them, you definitely do. Raccoons, foxes, hawks, eagles, weasels, rats (rats will kill and eat a chicken although bantams and chicks are more at risk), cats, dogs, snakes, etc.
So build a chicken palace and give them all the enrichment you can, but knowing that they’re safe is #1. After all, they can’t be happy if they’re dead. I specifically grow alfalfa and other vegetables (like sunflowers) for them in my garden.
What should I do if I suspect my birds have Avian Influenza (or another disease?)
You should contact your local FDA (or whichever governmental agency deals with Avian Influenza reports) immediately, keep the birds contained, and minimize you and your family’s contact with your birds, and do not give away or sell the animals or their products. The agency will send a tester out and will give you more information–follow their directions.
If they test positive, survivors (should there be any–however unlikely due to the virulence of the disease) will have to be culled and properly disposed of which the agency will do, and since the virus can survive for a period of time in the environment, you will be asked to refrain from keeping poultry for a few months up to a year depending on state guidance.
While it may be heartbreaking to lose your birds, Avian Influenza on its own is a death sentence for your birds to begin with (with a near 100% mortality rate for galliformes–chickens, quail, turkey). Our responsibility now is containment so others will not have to lose theirs (since if a disease vector like a wild bird comes to your property, they will carry it to someone else’s.)
Please see below for a recent (2025) example of how it burns through a flock and what kind of mortality rate poultry are looking at:
What should I do if I have been exposed to Avian Influenza and have now developed symptoms of illness?
After you make the report about your flock and it comes back as positive for AI, monitor yourself for signs of illness. If you become ill, call the agency you reported your flock to for guidance, as well as the CDC. Usually, you will be given a course of antivirals (to prevent you from concurrently catching a human flu virus and thus increase the chance of AI and the human flu exchanging genetic material and mutating) and asked to quarantine for a set period of time. If you have a sudden onset of severe symptoms, call ahead to the emergency room and let them know you had been exposed to AI via your flock before going in, or if you plan to call an ambulance, let them know as well so the providers and emergency response teams can properly prepare. Always follow your healthcare team’s directions.
Please note that human cases of HPAI (bird to human) tend to be very severe with a high mortality rate–an acquaintance of mine (who is, ironically a show bird breeder) caught it after being aerosol’d by a pigeon on her way home from work and she said from the time of contact to when she found found on the floor and taken to the hospital was mere hours, so it is important to report symptoms of any illness if you’ve had exposure.
Will my birds be culled if I am near someone who had an outbreak?
No. If you’re in a red zone (which is where you’re within a certain radius of a positive case), you’re asked to keep a closed flock for a period of time–no new birds in or out of your flock for the time being. You may be asked to test your flock as a precaution.
I’d like my birds tested for diseases, where can I get that done and what is the cost?
You can get them tested via a private veterinarian, through your state agricultural extension cooperative if you’re in the United States, or if you participate in the National Poultry Improvement Plan (NPIP) program. All of these will have out of pocket costs except NPIP if you are in a state such as New York that subsidizes NPIP tests. NPIP is voluntary and has yearly testing for several diseases (their AI testing program is every 6 months in NYS), it also allows you to ship eggs and birds across state lines.
Different states’ NPIP programs may have additional tests beyond AI, Fowl Typhoid, Fowl Cholera so you should check to see what yours includes. I am NPIP certified despite the fact that I don’t ship birds or eggs, but I like the peace of mind and the no cost effort of having tests done every year.
I recommend also sending out for fecal exams once a year to keep on top of intestinal parasites, such as coccidiosis and roundworms. If you have your own microscope, you can also do your own fecal floats and learn to recognize some of the more common parasitic infections.
A Final Note
There is time to be on high alert and there’s time to panic, I don’t necessarily think we’re at the panic stage yet although we could be eventually. While the pandemic potential would be horrible (because HPAI of the bird to human variety has a high mortality rate, although the bird to cow to human one does not as of now), especially for marginalized communities and poor countries, the main concerns tend to be about our food supply chain since egg and chicken is in everything–but alternatives to poultry meat and eggs do exist so it’s unlikely humans as a whole would starve. I would however, note that historically, eggs and poultry were a cheap source of protein especially for the poorer communities, so they tend to be disproportionately affected by interruptions in this food chain. It is also why changes in commercial chicken keeping must weigh the benefits with the cost of implementation.