Avian Pox in Chickens - Warning, Graphic Pictures (under construction)

Avian pox is a relatively slow-spreading viral disease in birds, characterized by wart-like nodules on the skin and diphtheritic necrotic...
By BYC Support · Jan 10, 2012 · Updated Mar 18, 2012 · ·
  1. BYC Support
    Avian Pox
    (text courtesy of Mississippi State University, photos by BYC)


    Avian pox is a relatively slow-spreading viral disease in birds, characterized by wart-like nodules on the skin and diphtheritic necrotic membranes lining the mouth and upper respiratory system. It has been present in birds since the earliest history. Mortality is not usually significant unless the respiratory involvement is marked. The disease may occur in any age of bird, at any time. Avian pox is caused by a virus of which there are at least three different strains or types; fowl pox virus, pigeon pox virus and canary pox virus. Although some workers include turkey pox virus as a distinct strain, many feel that is identical to fowl pox virus.

    Each virus strain is infective for a number of species of birds. Natural occurring pox in chickens, turkeys and other domestic fowl is considered to be caused by fowl pox virus.

    Fowl pox can be transmitted by direct or indirect contact. The virus is highly resistant in dried scabs and under certain conditions may survive for months on contaminated premises. The disease may be transmitted by a number of species of mosquitoes. Mosquitoes can harbor infective virus for a month or more after feeding on affected birds. After the infection is introduced, it spreads within the flock by mosquitoes as well as direct and indirect contact. Recovered birds do not remain carriers.

    Since fowl pox usually spreads slowly, a flock may be affected for several months. The course of the disease in the individual bird takes three to five weeks. Affected young birds are retarded in growth. Laying birds experience a drop in egg production. Birds of all ages that have oral or respiratory system involvement have difficulty eating and breathing. The disease manifests itself in one or two ways, cutaneous pox (dry form) or diphtheritic pox (wet form).

    Dry pox starts as small whitish foci that develop into wart-like nodules. The nodules eventually are sloughed and scab formation precedes final healing. Lesions are most commonly seen on the featherless parts of the body (comb, wattles,
    ear lobes, eyes, and sometimes the feet).

    Wet pox is associated with the oral cavity and the upper respiratory tract, particularly the larynx and trachea. The lesions are diphtheritic in character and involve the mucous membranes to such a degree that when removed, an ulcerated or eroded area is left.

    Hen with severe dry pox and wet pox
    pox_1.jpg pox_2.jpg
    Before plaque removal
    pox_3.jpg pox_4.jpg
    After plaque removal
    pox_9 (Small).jpg pox_10 (Small).jpg

    Fowl pox is readily diagnosed on the basis of flock history and presence of typical lesions. In some cases, laboratory diagnosis by tissue or transmission studies is necessary.

    There is no treatment for fowl pox. Disease control is accomplished best by preventative vaccination since ordinary management and sanitation practices will not prevent it. Several kinds of vaccines are available and are effective if used properly.

    Vaccination of broilers is not usually required unless the mosquito population is high or infections have occurred previously. The chicks may be vaccinated as young as one day of age by using the wing-web method and using a one needle applicator. All replacement chickens are vaccinated against fowl pox when the birds are six to ten weeks of age. One application of fowl pox vaccine results in permanent immunity.

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Recent User Reviews

  1. shessowitte
    "Great information"
    5/5, 5 out of 5, reviewed Nov 12, 2019 at 12:20 AM
    I’m so happy this article is here and explains that it’s pretty common. I thought it was preventable or my fault somehow. Only one chicken showing signs, so she is quarantined.
  2. FluffTheDuck
    4/5, 4 out of 5, reviewed Jan 8, 2019
    It is very educational. However, I did want to know if the disease will end up killing the bird.
  3. k2panman
    "Just the info I needed to diagnose my chicken"
    5/5, 5 out of 5, reviewed Dec 11, 2018
    good pictures! An informative and to the point article. Only thing missing is the name of the vaccine and where to get it.
    casportpony likes this.


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  1. Chelsea-85
    Thanks for the info. I had a white 8 weeks old chicken that had dry fowl pox. I didn't separate her; I put vitamins into their water and for 7 days I smeared her wattle and combs with a cream bought from a vet shop. She recovered after 10 days. Now she lays an egg everyday :)
      penthesillia likes this.
  2. Wee Farmer Sarah
    Thanks for the info. Apparently this is what just started showing up in my flock. They seem otherwise healthy. Good appetite, normal behavior and laying well. So they should pull through this???
  3. SurferchickinSB
    Really good article.
      casportpony likes this.
  4. bluebirdnanny
    Thankfullly I have never had/seen this. I do get frostbit sometimes but nothing like this!
      casportpony likes this.
  5. casportpony
    1. Kiki
      Is this still under construction?
      SavKel&RynKel and casportpony like this.
    2. casportpony
      Yes, try to figure out what pictures to use.
      KikisGirls likes this.
  6. Frutfarm
    I found a wild bird with avian pox fluttering on the ground, not doing well. My chickens were all staring at it, but seemed to have kept their distance. What, if anything, should I do with my chickens. My bantams have never had any vaccines, but I know our standards (they're about 5 weeks old)are vaccinated before they were shipped. But, I don't know if avian pox is one of those. I'll check their website. Should I worry about vaccinations for the bantams just based on finding that wild bird?
      casportpony likes this.
    1. melle1980
      Put apple cider vinegar with the mother in their drinking water. Put a tbsp of ACV for every gallon of water. It will boost their immune systems. Sometimes I throw chopped garlic and hot peppers into a little boiling water and let them sit, when it cools I add it to their water.
      casportpony likes this.
  7. nanasnuggets
    We found a robin on our property that apparently died of the avian pox; we've bleached all surfaces that we could. Our chickens don't usually travel in the areas that this bird was found. My question is - can the girls catch this virus from the robin? Is it too late to vaccinate them?
      casportpony likes this.
  8. ellend
    *Vaccine: must be used ALL at once: cannot be stored. Avail. thru catalog / online under "poultry vaccines." (Around $12.00 plus shipping & handling, for a multi-dose--many chicken--vial.) It comes with a VERY SHARP small plastic-handled two prong tool. You pluck a small spot on the wing, check the area (with back-lighting) to make sure no blood vessels are in the way. Then dip the tines in the vaccine, and poke the tines ALL the way THROUGH the wing web skin. (From the underside.) Directions come with the vaccine, or are available online. If the vaccine "took" the bird is supposed to develop a small scab at the vaccine site.
    *Vaccination while the bird HAS pox: Not advised. It won't help, and it will further stress the bird's immune system, increasing the likelihood of her developing a secondary infection. Vaccines take a week or longer to BEGIN working (usually two): The vaccine STIMULATES (stresses) the immune system so that it starts making antibodies to fight the invader next time it appears. Those antibodies take TIME to be made, and made in enough quantity to do the job. If your other birds appear healthy, it might be worth a try; if they haven't been infected YET, and if they don't GET exposed to the virus (have it actually enter their system) in the time it takes the bird to start producing enough antibodies to fight infection, they might not get pox at all, or might get a much weakened version of it. (The vaccine doesn't cause infection--it just injects the dead or weakened virus which the immune system then responds to as to "an attack.") The bird who HAS pox is developing it's own antibodies as a response to the viral infection--that's what is happening while the bird looks sick from the virus, and that's why the bird gets better--her new antibodies manage to fight off the virus before the virus debilitates her beyond survival. Again, I don't know that the antibodies for avian pox last thru more than one year. Antibodies have varying effective spans, but even if the effectiveness is reduced with time, a bird with antibody "memory" in her immune system will have a faster and stronger response to the presence of the virus than an unvaccinated bird, or one who has not had pox before: hence, the second time a bird gets it, it should be milder, unless the bird's condition, age, etc. has worsened. Vaccines do NOT provide immediate protection. Immune globulins (Ig's) provide immediate, but very temporary, protection from disease, but it's not cost effective to develop Ig's for poultry infections. (If your UN-vaccinated person gets a contaminated wound--meaning non-sterile--he will be given Tetanus Ig for immediate protection, and vaccinated for long-term protection (i.e. the production of antibodies and the cellular "memory" of invader Tetanus protein recognition.)
    *Bleach: Will not stop the spread of pox, since it's mosquito-bourne. It will, however, help keep secondary infections at bay...
      Imprfctme and SurferchickinSB like this.
  9. Alliesmom
    How long after the bird is showing no signs should I wait to allow her back into my flock?
  10. horselover1999
    I have two hens that have the dry pox. I noticed about a month ago that there was mosquito larvae in a bucket of standing water. I really need to clean out those buckets.
  11. CDS85
    So what I'm understanding is that once the chickens get it, that you have to just let it run its course? About how long will they have it? Can you still eat the eggs and meat while they have this illness?
      helgason likes this.
  12. Pretty Chickens
    My pretty black tailed white bantams and I used red ink on them I do hope they get better
  13. hammytammy
    also can anyone explain the stunted or retarded consequence in young birds?
    does this just slow them down, or will they remain immature, unable to lay eggs or breed?
  14. hammytammy
    the fowl pox came and went in my flock. Except 1 hen who got the wet form. everyone else is done--its been 2 months or so. why didnt she shake it? does it turn chronic at all? shes cranky but gets around fine. still feisty.
  15. ellend
    Antibiotics will not affect ANY virus. If she does not have a bacterial infection (secondary to the pox) you are messing with her natural flora (the GOOD bacteria that she needs) by introducing antibiotics, which kill "good" bacteria as well as "bad." That being said, some people do treat to try to PREVENT secondary infections with antibiotics; that can backfire, because when her NORMAL flora are killed off, that leaves "real estate" open for more pathogenic strains of bacteria to populate. If she gets a bacterial infection, treat her. If she is doing all right, let the virus run it's course (as it will ANYWAY.) If you ask YOUR doctor for antibiotics when YOU have a virus but no bacterial infection, hopefully he/she will tell you "NO." The days of handing out antibiotics to keep patients happy, when their use is not justified medically, are over; we now know how much harm that can cause.
      Frutfarm and jzinius like this.
  16. ellend
    To prevent secondary infections WHILE and immediately AFTER they are infected with Fowl Pox virus, disinfecting will help reduce the bacterial pathogen load, and hopefully reduce secondary infections. Those who had pox shouldn't get it again (although some will) but any who didn't get it can (and are likely to) in the future, if they aren't vaccinated before being bitten by a carrier mosquito. Fowl pox is not contagious to non-avian species; other birds can get it. If you vaccinate a sick or infected bird WHILE it is sick, infected, or recovering, the vaccine challenge may further deplete his immune system and you will have a higher risk of secondary infection or of the bird not recovering from the fowl pox virus. The first post, from Mississippi State University, is very good.
      Frutfarm likes this.
  17. jackhorn01
    Can fully grown adults be vaccinated?
      Thorn Fulford likes this.
  18. zinniaseeds
    I noticed my Petunia has the lesions on her comb yesterday when I was holding her. I have not noticed any other symptoms. I bleached their water container and am cleaning well. My stuff is easy to clean. Now that I have read here about the other symptoms, I will watch. DANG! I never had this problem when I had chickens 30 years ago. I thought antibiotics did not help a virus...Is is just for the secondary respiratory infection? Is that not part of the virus? We have a huge flock of wild turkeys that hang around our property...I wonder if they all have this. I added cider vinegar to their water and probiotics. Do I need to get antibiotics?
  19. ellend
    Vaccine is available online. It is very inexpensive, but you must add on shipping to keep it cold.
  20. Stylishone
    So what vaccine is everyone using to treat the avian pox? I thought there wasn't one to use, that it needed to just run it's course?
  21. Triplell
    Ugh !!!! I have fowl pox in my flock. The rooster that has it really bad. I was looking him over and noticed that his ears were really crusted over. He had a hard time crowing. I removed the crust from his ears and what looked like puss came running out is his ear
    I called the Vet on Thursday and started antibiotics on Friday. If no improvement on Mo day I will take him to the vet for a super antibiotic. So now I am treating everyone as a.precaution for the secondary infection. I have to start filling the bators for January hatching for the 4-H ERS and the FFA. I sure hope they don't stop laying before hand and allow me the withdrawal time.
  22. scwheeler24
    To help their recovery, I would add some extra nutrients to their diet. They'll be lethargic, pale, and not eat much. Adding Nutri-Drench to their water will help with energy, Performance Poultry or Rooster Booster Vitamins and electrolytes with lactobacillus to their water may help. give them food they like to help their appetite. Peas, BOSS, oatmeal, add some brewers yeast and garlic to their feed, a recipe they'll like is 1 jar unsweetened applesauce, 1 egg yolk, 1 tsp molasses or 2 tsp of Nutri-Drench, 1/4 - 1/2 c plain unsweetened yogurt. But the top thing would to be add the electrolytes and vitamins to their water.
  23. scwheeler24
    Just to clarify, my statement about eating the meat may be confusing. I'd certainly eat the meat but wait till they have completely recovered.
  24. scwheeler24
    Vaccines are a one time thing. There are 2. for young chicks and older than 6 weeks. If you get as chicks, they require a follow up at 6 weeks. It is a live vaccine, so once you mix it that's it. You cannot reuse it. If you order it the vaccine itself is not expensive, but it must be packed in ice so the shipping is $$. It cost me $40 for my flock, that was for both. I think each vial is enough for 100 doses? Somewhere like that. But it's no good after 24 hours. The problem for me is my vet or any other does not have this, and when acquiring a couple chicks at a time or hatching it can get pretty expensive. I don't know if I'll vaccinate any more of mine, just let it run it's course., especially if it isn't usually fatal or contagious to humans. I don't know if I'd eat the meat. I'd at least wait till they have recovered completely first. That just doesn't sound very appetizing. The egg production is so low if you decided to not eat them, it's no big loss. I don't think (but don't know for sure, I am guessing) that the eggs would be okay, it's a virus among them and isnt contagious. Clean the coop AFTER it is gone, but personally, being from a mosquito, any new fowl you get will most likely get it eventually, especially if it is in your area.
      Frutfarm likes this.
  25. VickiC
    My normally active friendly Wyandotte rooster has become lethargic and is standing with hs head down. He is not crowing idn the morning and is not moving far from the coop when I let them out in the morning. I have noticed black spots on his comb and also he is scratching his ears and opening his mouth like he has blocked ears. He also shakes his head a lot. Can someone help please ? Our local vet doesn't seem to know much about birds ( from past experience) Vicki
  26. Chicken Goddess
    Can it kill my chicken? is there a possibillity of her surviving
  27. tomdeggeater
    According to the article at the beginning of this, there is no cure. It just has to run its course.
      Frutfarm likes this.
  28. Chicken Goddess
    Is there a cure or treatment for avian pox? my chicken has it and im worried.
  29. tomdeggeater
    Although the above article refers to the flu virus, most viruses react the same. The important thing is to remember that a virus is not affected by antibiotics; which are designed against bacteria. The antibiotics are given to chickens with the pox for secondary bacterial infections-opportunistic given that the chickens immune systems are weakened by the virus.
    Also, I would fry the eggs on both sides and hard cook the yolks...
    If the meat gets to over 165°F, it will be ok to eat.
  30. tomdeggeater
    Fortunately, the influenza virus is not all that hard to kill.
    ---Heat will do it, 160 degrees F. or higher. Your dishwasher, washer and dryer and stove are lethal to the virus on surfaces at this temperature.
    ---To be safe, OSHA recommends cooking poultry to an internal temperature of 165 degrees to be sure it's fully cooked clear through.
    ---Alcohol will kill the virus, either in a 70% solution or in a waterless hand cleanser that has at least 60% alcohol content
    ---Lysol and other antiseptic cleansers that are labeled effective against viruses will kill it on hard surfaces if used as directed. Be sure the label specifically states that the product kills influenza virus, not just bacteria. A virus is not a bacteria.
    ---Chlorine bleach in a dilution of a quarter cup bleach to a gallon of water will kill influenza virus, as will chlorine-containing scouring powder. (Bleach solution deteriorates quickly, so you have to mix a new batch every day.)
    ---Even plain sunlight will kill the virus after a period of several hours of direct exposure.
    ---Time will kill it if it's dried out: after two days or so, dried-up virus in dust dies. In moist conditions, however, it can survive much longer.

    But you can't kill the virus by

    ---Freezing or refrigerating it
    ---Washing it off with soap and water.

    This is important to understand: To be sure, wash your hands thoroughly, but know that you are mechanically removing the virus from your skin by friction, then rinsing it down the drain rather than killing it. This is true even if you use antiseptic soaps, so don't bother using a special soap.
    If you are not thorough with your scrubbing and rinsing, virus particles will remain between your fingers and around and under your nails. To be sure you've scrubbed long enough, sing the alphabet song through twice before you put your hands under the water to rinse them. Washing your hands is still the best way to prevent flu, just be sure you do it properly or it won't work.
    Thanks to: http://familyflublog.blogspot.com/2006/03/what-kills-avian-flu-virus-and-other.html
  31. ellend
    Fowl pox is not contagious to anything except other birds. Eggs can eaten during the course of the the disease; they will not be affected, and you can't get fowl pox, period. The vaccine won't harm the edibility of the eggs either; vaccines aren't medications. Chickens with pox may, as noted above, get secondary bacterial infections while they are immune compromised from the pox virus. Bleaching / disinfecting will help keep down bacterial transmissions; it doesn't do anything to control pox, as it is solely mosquito borne. Fewer mosquitoes (screening?) reduces chances for pox, as does the vaccine, given BEFORE exposure to the virus. Don't bother separating birds with pox unless they are outwardly stressed; it is likely the others have already been exposed by the time you see lesions, and also--mosquitoes can fly. If the bird contracts a secondary infection, separating might keep the others from getting the secondary infection. The vaccine must be shipped cold, and kept refrigerated. Once reconstituted, you have a short time to use the vaccine. (1/2 hour? hour?) It must be disposed of after that; my instructions said burn it. A VERY sharp 2-pronged stabber (without a protective cap! Don't, as I did, reach into those packing peanuts to find it!) You mix the liquid with the dry, mix well, dip the stabber into the vaccine, and poke the prongs of the stabber THROUGH the web of the wing, looking to see where the vessels are first, so you don't hit them. (You pluck a little spot so you can see, and use either sunlight or flashlight on the opposite side of the wing (like lighting up a pumpkin) to look for vessels to avoid. The vaccine is dyed dark blue, so you can see the spots where it went in. It is a very fast and easy process. Package insert is very detailed, and videos are available on YouTube. A positive reaction (meaning the vaccine "took") is supposed to be redness at the site. None of my 8 showed anything--hope my vaccine was good! Remember; it is a 1,000 dose vial, but you can't store some for later, or store it for later in the day to share with a friend. If your feed store sells it, wonderful! The vaccine is cheap (around $11.00) but the shipping with cooler and ice packs is not! It's probably not surprising that some birds get lesions more than once; I've noticed that redheaded humans tend to get chickenpox twice, whereas most of us get it only once and then are immune. The second case will probably be lighter, due to partial immunity.
  32. scwheeler24
    It's a one time vaccine. If it is young, usually a booster is needed, but that is it.
      Frutfarm likes this.
  33. scwheeler24
    It is a live vaccine. You must vaccinate all chickens at once, then the vaccine is no longer any good.
      Frutfarm likes this.
  34. ellend
    My first (stray) bantam also got fowl pox more than once; fortunately not severe infections. Re: vaccines; is this a yearly vaccine, or a one-time per bird? Is a second round required a few weeks after the first?
  35. sunshinestatechickens
    My chickens have had these exact same lesions twice now??? I thought they are immune after the first time? Also, I didn't see an answer as to whether if it can affect us, and if we can still eat the meat and eggs while they have this? Thanks ahead of time for any answers. Don't know what I'd do without this site!
  36. maggs470
    Update: From what I was able to gather, avian pox is a contagious viral infection and not affected by antibiotics. It lasts about two weeks and does not occur suddenly, it's a slow acting thing. Cleaning the feeders, waterers, and contact surfaces with a dilution of bleach & water will effectively decontaminate the area. My hens have all gone thru cutaneous fowl pox and are doing very well. YAY! Thank you BYC!
      Frutfarm likes this.
    1. Vicky M. Miller
      How long did it take to rub it's course on your flock? How many are in your flock?
  37. frizzle lilly
    if this is spread by mosquitoes how do you stop it from reoccuring? What will cleaning with the bleach do?
  38. PrincessKristin
    Thank youall for your advice, i have noticed about half my flock has these black wart looking things on them, and a couple are lathargic ( sp?) I have started them all on Duramycin, which vet said will cure any bacterial infections.I am worried about my Peacock though. He has no signs of anything, ( keeping fingers crossed)
  39. maggs470
    Question: Do we have to isolate the hen from the rest of the flock if she has fowl pox? One of my 5 hens have the (dry) fowl pox and I haven't seen signs on the other girls yet. Also, what is the duration of fowl pox from start to finish if it's only one bird?
  40. Jeffrey1
    Since it's spread by mosquitoes, do you have to disinfect daily, or at all?
  41. cowgirlupinok
    Fowl pox will not get into other farm animals that are not of the avain class. It can get into other forms of birds that may be on the farm, though. You should NEVER vaccinate a bird already showing symptoms. Once the fowl pox has ran its course the bird will be immune (just like the human form) and won't get the fowl pox again. We had a huge outbreak (we have over 200 chickens) and did loose some birds. Partly due to wet pox, partly due to the heat, and partly due to the combination of both things together. You can get an antibiotic from the feed store and place it in the water bowl for the birds to keep secondary infections at bay (like respiratory infections that are normal with the pox virus), keep their pens cleaned daily, use apple cider vinegar to help neutralize the bad bacteria. Egg production will slow or halt completely but will return later (ours just started laying again). The outbreaks can be long lasting as some birds don't catch it until other birds are finally getting well. We have battled the fowl pox for almost 2 months and just today have no signs of any outbreaks on any of our birds. My plan is to do a final disinfecting cleaning tonight with a 10% bleach solution and let the pens dry before placing my birds back into them. I am fortunate enough to have enough land that I have several bird coops and runs so I am able to do this...if you are not then place the birds in a carrying cage or clean while they are free ranging for a little bit. You want the bleach to have time to dry before placing the birds back into the pens.
  42. LoveChickens123
    is it contauguis to other farm animals?(worried)
  43. LoveChickens123
    is it contagious to other farm animals ( very worried)
  44. alienkitties
    Okay, but is the chicken still okay to eat??
  45. birdpond
    So, the vaccine works on birds already showing symptoms, or only on birds not yet affected by pox? Also, will supportive therapy with VetRx help until recovery? THANKS!
  46. orangecatrex
    ll this information sure eases my mind. I noticed today most of my flock is suffering from these sores on their combs and wattles. I doctored it with some purple wound dressing (purple lotion) Hopefully this will help dry them out. I was almost hysterical when i noticed it, but after the doctor session and a quick trip here to BYC and my mind is at ease. Thanks community
  47. blmack
    I have two hens with these things on their combs. Will the vaccine affect their eggs in any way? And does it have to done with a shot or is there an oral medication?
  48. clucky3255
    i am asking a question on this topic......in emergencies ... so if u have any helpful information....that yould be great THANKS YALL!!!
  49. tangledgardens
    Yes there is a vaccine. My research tells me this is not contagious to humans. My experience has taught me that the pox isn't deadly but a secondary infection ie. respiratory infection can be deadly. The second rooster I wrote about earlier seems perfectly fine. The antibiotic I got from the vet worked on the respiratory infection and slowly his pox are going away. No one else in the flock is sick at this point. Fingers crossed. Have yet to vaccinate.
  50. txchickster
    Is this dangerous to humans or deadly to my chickens? I have noticed a few spots like the ones pictured on one of my reds now I am concerned with what vaccines they may or may not have received and if they will all be alright.

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