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Avian Pox How To Treat Your Chickens For Avian Pox

Avian pox is a relatively slow-spreading viral disease in birds, characterized by wart-like nodules on the skin and diphtheritic necrotic...
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    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.

    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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  1. 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?
  2. 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...
  3. Alliesmom
    How long after the bird is showing no signs should I wait to allow her back into my flock?
  4. 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.
  5. 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?
  6. Pretty Chickens
    My pretty black tailed white bantams and I used red ink on them I do hope they get better
  7. 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?
  8. 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.
  9. 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.
      jzinius likes this.
  10. 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.

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