Thursday, February 7, 2013

Should I Vaccinate My Chickens / Poultry for Marek's Disease?

*** UPDATE ***
New information! Click link below.
Vaccination Makes Marek's Disease MORE Dangerous!

Natural Chicken Keeping Question of the Day:

Hey there!
First off a THANK YOU for this wonderful website. I can't tell you how much I've learned from you guys!

I have a question that is driving me insane, because I can't get any definitive or good answers about, that I was hoping you could help me out with:
My husband and I currently don't have any chickens, as we are in the process of moving to a bigger ranch here in Texas. We will be raising a small herd of grass-fed cattle, and free-range chickens, organic vegetables, etc. and plan to do everything as holistically, organic, and naturally as we can. The immediate and main reason is for us to have dependable, Non-GMO, chemical free food for our health, but who knows; a couple years down the road we may try selling some grass-fed beef, pastured eggs, and poultry....

But the question I keep coming up against is whether or not to vaccinate our new chicks when we get them in a couple months for Marek's or any other diseases. I would really rather not, since as I said we want to go the natural route, but was wondering if you guys had any insight into pros and cons that may sway me one way.

Our flock will be about 8-10 birds for the first year, and eventually if we end up selling some pastured eggs or poultry, of course we would have more birds. If we do that, we will likely not go for an Organic certification, with such a small operation; even though the feed our chickens get will be Organic, Non-GMO, and we will be using Organic/Natural pastures, and farming practices. As I understand it, you can vaccinate chickens who will even be certified Organic, (this could be wrong, but the majority of what I've read says it is allowed) but I'm more concerned about any possible dangers or issues that vaccinating our flock could have on us since we will be consuming their eggs and meat. 

So far almost everything I've read, and people I've spoken to all say YES, ABSOLUTELY vaccinate for Marek's, but they can't tell me if there are any dangers from this, and as most of those people have been "non-organic" conventional raisers of chickens, and traditional vets.

So, just wondering if you may have any info that could help me out. I'm so confused and stressed about making the decision to vaccinate the chickens or not; that I'm starting to lose sleep! I would REALLY love to hear your thoughts on the matter, and see if you can help!
Thanks so much for everything you do-your hard work to help chicken owners, is SO very much appreciated!! :)
Cynthia, in Texas

Leigh Says:

First of all, thank you for your kind words about the Blog! I feel so lucky to have such wonderful sources of knowledge (Vicki, Tom, Karen, Chrissy, Jane, Sue… and that these super folks share their knowledge so freely with the rest of us! Without them, this blog would not be.

Now then…
I do not vaccinate my flock for the sole reason that I do not wish to add any extra chemicals, medications or “additives” to my birds. That said, if my flock ever did have an issue with Marek’s, the game would change out of necessity.

I would ask around and find out if any of the past owners of the new property ever kept poultry on the land. Marek’s can be present in the soil for years after infected birds have left.

Most folks never have a problem with it, but for the few that do, it can be an ugly disease!

Vicki Says:
There are dangers to Merek’s and any other inoculation you give your kids, poultry or cattle. It sounds to me you eventually need certification for Organic selling, so you will need an NPIP certification and that requires testing. With any type of inoculation you are in fact giving the disease to your birds so they can build a resistance. You would not be able to bring other birds on your property unless they too were inoculated or they would be exposed to the Merick’s your inoculated birds are sloughing off.
With inoculation you can rest easy that your whole flock will not be wiped out from this disease. I do not inoculate my birds, however, I reserve the right to choose to do so if I ever hear of any type of disease in the area and if I expand my area of showing.

Justine of Les Farm Says:
I personally wouldn’t. I don’t think it’s necessary.

Tom (Life With Chickens) Says:
I don't and won't vaccinate. My only thought is it depends on the Texas laws (and trade organization rules) concerning farms and the legal selling of birds. Not just craigslist sale. But it sounds like you may want to do this legit and if that is the case you need to do whatever Texas says you need to do.

(Note: While there is no Texas law stating small, privately-owned flocks of poultry must be vaccinated for Marek’s, we encourage folks to comply with the rules governing other state or local certifications, when seeking such certifications.)


  1. I definitely would.
    It is an awful illness and the mortality rate is almost 100%
    Having lost one of my girls to this terrible, debilitating disease, I would not hesitate to vaccinate. x

  2. Vicki states:

    "With any type of inoculation you are in fact giving the disease to your birds so they can build a resistance."

    Based on that I have a question. When chickens - or any other animal - are in the "wild", they are exposed to many possible pathogens/diseases. Even when there is quite a disease load, those who have strong immune systems survive, build a resistance, and pass the resistance on to offspring. The Swedish Flower Hen breed may be a good example of this in our time as they seem to have survived in the "wild" without human intervention. Presumably the strong/healthy survived to produce a strong/healthy breed.

    With that in mind, would it be the more natural route to allow the birds to develop naturally - without vaccination - build natural resistance, and therefore breed a healthier flock?


    1. The vaccine is NOT the Mareks virus!!!!!!!! It Does NOT give them this disease but it is made from the turkey virus and it is NOT mareks itself.

    2. I agree w/ Vicki. Some hens are more domesticated than others and I wonder if they have a higher mortality rate when in contact w/ higher bacterial loads, viruses, etc.. Natural immunity is best even if you have to lose some birds. It's better for the health of the offspring and the breed in the long run. I have very limited experience however. This is just my opinion

    3. realsis77 is correct vaccinated birds do NOT shed the virus, the only way that can happen is IF the bird was already exposed and incubating the virus (thus shedding from disease and NOT the vaccine).
      Bought really really expensive rare breed birds and now I am losing them at 26 weeks old because they were not vaccinated and I failed to ask that they be.. It is devastating. There is NO treatment and NO defense. I am watching bright beautiful healthy birds go paralyzed one at a time. I suspect wild birds brought it, though it can travel on the air from dander form miles away....
      Vaccines are not toxins... understanding how vaccines actually work, and what each ingredient in them does, may alleviate fears.

      I have been 100% organic, but recently shared an order with a friend and she got them all vaccinated. 6 months later, I have to take my VACCINATED SPLASH MARAN to the VET. She has Mareks. UNDERSTAND, she was VACCINATED and SHE has but my entire flock at risk now because why? SHE WAS INJECTED WITH THE VIRUS! I am ANGRY and HURT. I should have stuck to my guns. At least if you do not vaccinate and you get mareks, the host and disease die. With vaccination, the host lives on to spread the disease the rest of it's life! FREAKING LOVELY!

  3. Leigh says " I do not vaccinate my flock for the sole reason that I do not wish to add any extra chemicals, medications or “additives” to my birds. That said, if my flock ever did have an issue with Marek’s, the game would change out of necessity."

    Once you have a bird that is identified as having Marek's it will be too late to start vaccinating as it will be in your flock and you should expect it to run through your birds. You will by necessity be depopulating your flock and starting over.

    If you choose to not vaccinate then I would strongly advise you to keep a close flock. The virus is transmitted from bird to bird not from the mother through the egg, so an exception to this rule is you may get hatching eggs, day old chicks from a hatchery or from a breeder that has a closed flock. I do not vaccinate because I have a closed flock. By the way, this includes not taking your birds off your property (like to a show) and then bringing them back in to your flock.

    I would personally rather eat a chicken that had been vaccinated with a virus in the egg or at a day old (the virus will give the chick's body information about the virus and trigger the chick to develop immune cells so it can fight off the virus before it can do any damage if it is exposed later in life) than eat a diseased chicken or have to kill my entire flock. The modified virus the chick is exposed to is acted upon by the chick's immune system and it is cleared from the chick's body. It is not a medication, a chemical or an additive, it is a vaccine.

    If you decide to bring in chickens from the outside world, then please be very careful about quarantining the new chickens and this includes not only isolating them from your flock but also not handling the new birds then tracking potential pathogens in to your flock on your boots or hands. Handle them last then clean up.

    1. You raise some very good points! Thank you for bringing up the information on the vaccine.

      It should be noted that I do keep a closed flock. When I add to my flock, it generally only from hatching eggs. The very few times I have added adult birds, I have kept them quarantined for some time, and then added one of my healthy birds to the quarantine area. After another few weeks (when the bird I added was still healthy)the new birds were allowed to free range. Because I breed pure bred birds, these flocks still do not co-mingle.

      But you are absolutely right for those who have mixed flocks and wish to add new birds in! The utmost of care should *always* be taken.

      This post was a sharing of a few people's personal opinions. Basically, someone out there asked if she HAD to vaccinate although she did not wish to. In effect, we wanted to give her permission to choose not to vaccinate while still being aware of the consequences of a Marek's outbreak. As she will be seeking NPIP certification, it is assumed she will be keeping a closed flock, also.

      For those interested in quarantine methods to help prevent disease from wiping out one's flock, please check out This Article.

      And please, always do what you feel is right for YOU and for YOUR FLOCK! There are 100 "right ways" to do any one thing. If your wish is to stay all natural, understand there are always associated risks, but with proper precautions, most folks can enjoy happy, healthy chickens for a long, long time.

      And thank you again for bringing up some very good and well thought out points! This blog invites the sharing of polite and informed opinions. We hope you will continue to share in the future.


    2. "It is not a medication, a chemical or an additive, it is a vaccine."

      IF it is a vaccine, it ABSOLUTELY - IS a medication, a chemical and an additive....and therefore a very important and personal decision. Which ever side of the decision you are on, do not be mistaken, it contains MANY things other than the pathogen it is developed for and that should factor into your choice.

    3. Actually it depends on the type of vaccine. There are many different types of vaccines the Mareks Vaccine is a Live attenuated vaccine which means it's a weaken state of the virus to allow the chicks body to build up its immune system against it there by helping the chick to become more resistant to the disease. So this particular vaccine technically isn't a medication, chemical or additive it's the actual virus in a weaken state.

    4. Merick's lives in the soil for years even without chickens. Once it's on your property, it's there for a long time. If you walk to your quarantine coop and then walk to your other one, you've just tracked Marek's over to it. Culling your flock and hatching out new chicks isn't going to make a difference. You either halt your chicken keeping for a few years or you just march on and try to keep your chickens as stress free as possible in the hopes your flock will become more or less Merick-proof. Hens which have built a resistance to Merick's, hatching out their own eggs, will pass that resistance on to their chicks.

  4. We inherited some grown hens, wo have not been vaccinated. Our neighbor about a mile down the road, who keeps about 130 chickens (natural, organically, though hers are not allowed to free roam but rather large runs) told us this:

    "Last year I lost about 75% of my flock to Mareks. Mostly it was the young ones who died, most of the adults were fine. It is sad in one way, but now I have chickens that survived Mareks and I will breed them for Mareks resistant birds. If I were not going to breed and simply wanted to limit population loss due to Mareks, I would vaccinate. I used to think, no way would I ever consider it, but it was sad and gruesome to see all those birds die the way they did."

    What little I know about the vaccine is that it must be given within 3 days of hatching, or the vaccine is useless. Too late for us. And since we have already visited this lady's farm and then returned to our own place, we may have brought it home with us. Or even the wind, it's been breezy here. We will see.


  5. I absoultely say yes!! Do vaccinate your birds against mareks disease. Mareks is a HIGHLY contagious air borne disease that can travel miles away in the wind. MAREKS IS EVERYWHERE. I've know of too many beautiful flocks that have been devistated by this disease!!! It is very sad and can be helped by vaccinating. In fact I'm going to vaccinate my babies wed. You can buy the vaccine for only around 19 dollars. I personally buy mine online from first state vet supply. Lets clear up some rummors about this vaccine. FIRST YOU WILL NOT GET THIS DISEASE FROM VACCINATION. It is NOT the actual Mareks virus you are injecting!! SECOND the birds do NOT have to be vaccinated at only a day old!! These instructions are for hatcheries. Of course the sooner the better before exposure to the disease however their is NOT a actual age limit to vaccinate. Of course it should be done as babies before they actually get exposed to the virus but if you feel your bird hadn't been exposed you CAN still vaccinate.
    THIRDLY it takes about one week for the
    antibodies to process immunity so they are
    NOT protected until AFTER that week. Their is
    absoultely NO reason NOT to vaccinate. You
    can disagree with me now but once your flock
    AND land has this virus you will understand
    what I'm saying. This virus can stay on your
    land for over a year!! Once ONE bird in your
    flock is effected with mareks the rest are
    carriers and can infect other birds. FACT it is
    a absoultely devistating virus that IS
    everywhere!! So consider this in making your
    decision. I defiently advocate the Mareks
    vaccine!! IT CAN SAVE YOUR FLOCK. I do
    respect the ambition to be all natural however
    they're Are risks involved. If you don't mind
    loosing your whole flock and waiting a year to
    repopulate then by all means don't vaccinate.
    But if you want to protect your birds then
    please vaccinate for mareks. This is the ONLY
    vaccine I give. I hope I'm not sounding too
    harsh but this is a VERY important vaccine.
    Its easy to administer and goes just under the skin of the back of the neck. It is easy to get and is NOT expensive. There is really NO good reason NOT to do it.

    1. how much of the vaccine do you give adult birds

    2. Anonymous - I'm sorry I don't know the answer to that question as I have an unvaccinated flock, but usually the dose will be on the box or bottle the vaccine comes in. Many times the dose is the same for adults as it is for chicks, but you can always double check with the manufacturer.

      I have been 100% organic, but recently shared an order with a friend and she got them all vaccinated. 6 months later, I have to take my VACCINATED SPLASH MARAN to the VET. She has Mareks. UNDERSTAND, she was VACCINATED and SHE has but my entire flock at risk now because why? SHE WAS INJECTED WITH THE VIRUS! I am ANGRY and HURT. I should have stuck to my guns. At least if you do not vaccinate and you get mareks, the host and disease die. With vaccination, the host lives on to spread the disease the rest of it's life! FREAKING LOVELY!

  6. I live in Lake Elsinore, CA and purchased a vaccinated day old chicks and 12 weeks later, confirmed Marek's disease! She was humanely euthanized for diagnosis. It's been about 6 weeks later and today, my "Pickles" is showing the same symptoms. There is no guarantee with vaccinating but I would do it anyway. It is such an ugly disease and it is breaking my heart. I work for a veterinarian and will probably have her euthanized tomorrow to end her suffering. : (

    1. I'm sorry for your losses!

    2. Where did you get those chicks from? I have some vaccinated day old chicks ordered and hate to hear that someone might be vaccinating improperly or not vaccinating at all especially sine I'm getting some to replace my losses from Marek's already.

    3. I had a vaccinated at hatching, 7 month old gorgeous rooster die an absolutely hideous death from Marek's. He was my flock's egg, hatched at a local, reputable place and brought home on day 2. Ow I have to worry about all of them. Forever. I have a broody bantam who I let have three eggs, and I have to buy $40 of stuff to do it at home for possibly two chick's when the bottle is good for hundreds and I will have to throw it away. I wish it was easier.

  7. Yes. Vaccinate your future heans or any birds you plan to grow out past about 8-12 weeks at least. In the organic program, including certified organic, vaccinations are allowed and encouraged. Marek's disease is extremely common although I'm only finding out that most people don't realize this. There are 5 forms of it and you can bet that lots of birds turn up with it, and die, and the owners never even realize that is what they died from. Some get sick, seem to recover, and then later die from the tumors. Sick birds don't keep laying eggs so you'll be feeding them just to watch them die. It is highly contagious spread through dander and manure. This is why it is a worldwide disease. Anyone with even a few birds has probably had it on their property already. It also causes blackhead in turkeys apparently. And it will persist on your property for up to 5 years I've heard so once it lands there it can linger for a long time and since chickens like to pick up every little speck on the ground they will find it eventually, contract the disease and spread it. It takes a couple months to manifest itself after they contract it so you never see it coming. The vaccine is cheap enough and will save you a lot of heartbreak. Also the vaccine is 95% effective. Take it from someone who learned the hard way.

  8. Mareks vaccine is not to cure Mareks but to prevent the frequency of shedding of the virus and the severity of the outbreak. Plus the amount of the vaccine given is so minimal it wont affect us humans. Regardless of vaccination chickens can still get Mareks either way.

  9. Vaccination of newly-hatched chicks with live vaccines has been widely used to successfully control MD since the early 1970s. However, vaccinated chickens still become infected and shed MDV. Vaccine breaks have occurred with regularity and there is evidence that the use of MD vaccines could be driving MDV to greater virulence. MD continues to be a threat and a number of strategies have been adopted such as the use of more potent vaccines and vaccination of the embryonic stage to provide earlier protection. Recombinant MD vaccines are useful vectors and are being exploited to carry both viral and host genes to enhance protective immune responses. The future aim must be to develop a sustainable vaccine strategy that does not drive MDV to increased virulence.

    1. Exactly right, Robert! There is a link to an article with this information in it up top. I think it's something very important to consider. I would rather breed birds that are healthy and less susceptible to Mareks than contribute to a disaster in the making... but sadly some folks have rampant issues with Mareks and have to make a decision between vaccinating or losing flock after flock.

    2. EXACTLY. What breeds are resistant?

  10. Most vaccines contain mercury compound which will pass to and be bound in the egg protein. From what I know eggs are important especially when placed in grape juice to bind and remove mercury and heavy metals from the human system. I am trying to find eggs from hens in Australia that are not vaccinated as I need to continue removing heavy metals and mercury from exposure i was subjected to. I do not want eggs that bring in mercury and chemicals from vaccines as these things are not detected until ten plus years after accumulation in the body. Mercury is the most toxic metal and binds to nerves and fatty tissue in peoples body for life. Extremely difficult to remove and will cause more problems than anything else in the long run to society. Most people do not understand this and have made it a controversial topic rather than one of caution and concern. But there is information if you google the right websites on mercury and vaccines and how they have debilitated humans for life.


    1. Many vaccinations are processed with thimerosal which does have some mercury in it... not a good thing for any of us! I am sure you have researched the benefits of chelation, Andre. I wish you the best of luck and hope you are able to become healthy again!

  11. I've owned chickens for the past 18 years and have never experienced a case of Merak's disease until just recently. Just 3 weeks ago my Silkie hen was running around happy go lucky and eating properly and then the very next morning she stopped eating and I noticed watery yellow-white greenish poop. She wouldn't eat anything for the rest of the day so I began feeding her on a 6 hour basis. She just turned 2 years old so I didn't think this could be Merak's disease because I thought only the virulent forms affected the younger set of chickens under 6 months old, but unfortunately my hen contracted the Cutaneous Merak form and I can feel the nodules all over her body right under the feather follicles as they are round and hard. She has them all over her upper neck and her head as well. These nodules did not appear until the 2 weeks after she became clinically ill. The beginnings of Merak's disease can be confused with other chicken illnesses. At first I thought she had Pullorum which is usually a baby chick malady, but her droppings were all white so I used a Sulfonamide for several days and she seemed to respond to the medication by the 3rd day and then her condition got worse the next day. So I switched to using Oxytetracyline because I thought she might some other illness and that didnt' seem to do any good after several days so I again switched to using Amoxicillin and Cefradine to see if that did any good. Nothing worked. Then I kept looking online and researching like a mad person and finally when I discovered her nodules beneath her feathers, I realized it was one of the forms of Merak's disease. She also has had her eyes shut since day 4 of her sickness and have not opened them since then. I have fed her religiously and kept her alive, but not realize I've prolonged her pain and suffering and will take her to be euthanized tomorrow. Just half a year ago she was raising a family and now she is leaving me just days after her 2nd birthday. This whole 3 week period has been a living nightmare and it all could've been prevented if she had been inoculated with the the Merak's vaccine when I bought her from a breeder. I guess she decided she wasn't going to vaccinate them and I didn't bother to ask. Now I have exposed the rest of my small flock of 11 chickens to the virus. I am living in a timebomb frame of mind waiting to see which have the immunity to withstand acquiring the disease and who else will follow suit in my precious Silkie hen's tragic path. I've put so much love and attention into raising her and now she is going to leave me at such a young age. I am totally crying and heartbroken. If you love your chickens as adoring pets, don't let this happen to you. It is a complete and continuous nightmare.

    1. I'm sorry for the loss of your hen. Sadly, many wild birds carry Marek's and it is hard to avoid exposure. Many, many birds are immune to this disease. I still can NOT advise people to vaccinate for this disease as studies have recently proven that all vaccinating is doing is creating a STRONGER version of the disease that is not affected by the vaccination.
      Losing a bird is very difficult, but vaccinating is not in the interest of the greater good in this case. Super Marek's is already here.

    2. I have to completely disagree with your stance Bulldogma as a chicken not getting protection from this extremely nasty virus is a death sentence waiting to happen so how is that in the interest of a greater good? Please elaborate. Since my Silkie hen's untimely passing in mid March, I've had a 2nd chicken (my fave Silkie Roo) fall prey to the same malady of Marek's. He contracted the internal and cutaneous forms of it and was spared the ocular, but still the result is going to be the same. I've taken care of him for 32nd day of his illness, feeding him on a regular basis every day. I thought he would make it perhaps, but I guess I was just hoping for too much. I discovered that when a chicken is fighting other forms of sickness, that is when the Marek's rears its ugly head. They are opportunistic and wait in the shadows of their insides hoping they will fall ill or fight some other disease so that they can take over and kill them!!!!

      How can you be against vaccination when the most that could happen if a chicken were vaccinated would be to lose their egg laying ability (for a hen) or a Roo going quiet and lazy if afflicted? They are protected against the internal cancerous invasions and cutaneous and ocular forms when vaccinated and will not die. Not having protection is almost a certainty that the chicken will acquire the virus at some point in time of their lives and put them at extreme risk of death from those invasive cancers and lesions. I cannot understand the philosophy or indifference against vaccination. That is why you get ALL VACCINATED chicks when buying from the store. I was wrong to purchase from a breeder and now I am suffering the consequences of that purchase. I've lost my fave hen and all her 7 chicks may follow in the same path as her. Only 2 Silkies and 1 Sebright I have are vaccinated against Merak's and they're completely fine and not sick at all. Walking on eggshells watching the remainder of my small flock to see who is next since the incubation from time of contamination if anywhere between 5 to 25 weeks. I have to clear the end of August to see who resists the terrible affliction as when they become symptomatic, it is certain death. Yes losing a bird (when they're your beloved pets) is extremely sad and it takes its emotional toll on oneself and I wouldn't wish this upon my worst enemy to go through what I've been going through. After this incident passes and whatever of my flock is left, I realize I will NEVER again obtain chicks that are not protected against Merak's. The devastation of this occurrence is enough to convince anyone that you should PROTECT your flock form his horrible disease!

  12. I purchased only Mare is vaccinated chicks to start my flock two years ago. Several of those birds contacted the disease anyway and died. I think the vaccine (like our flu vaccines) means that might still get the illness but maybe have a milder reaction and fewer deaths. I have 21 eggs incubating now and will probably vaccinate them. I did not vaccinate the last batch but only had 4 chicks. My birds free range most days...neighboring flocks, wild birds and the wind carry I'll vaccinate against it (and only it)most of the time. Just a personal decision.


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