Confirmed Marek’s. Moving forward.

[Closing Time]

I’ve found wonderful guidance from the BYC members so far in my very short chicken journey. Now I find myself in a group I was hoping to not join.

We had a very small flock (1 polish roo who showed up one day in September last year and started this journey for us) and the three BAs I got for him to begin our flock. The BAs joined us in October as 16 week pullets (we got started pullets since he was already 6-ish months old). They were vaccinated for Marek’s. No idea of the Roo’s status (and he is honestly such a nice boy, we weren’t sure how he would mature but I love this bird).

You can take a look at my post history but long story short, one hen became ataxic and developed neuro symptoms back in January that didn’t quite line up with Marek’s and was dx by two separate vets as injury related. We convalesced her for 3 months to give her a chance. One of our other hens came down with something funky just this past month, provided a breadth of treatments. Both girls ended up dying within 24 hours of each other and were sent off to Davis for necropsy. Both came back confirmed Marek’s (see pic).

Now I find myself with 2 exposed chickens and a contaminated space. I have 4 almost 12 week pullets (2 EEs and 2 BAs) that I have been growing in a temp set up. Was planning on introducing them to the coop next weekend. And I had ordered 3 more to make up for the loss of the last two (2 SS and 1 EE). All are/will be vaccinated. But so were my BAs and they’re both gone before a year old.

I have read enough on here to know this happens and people mitigate moving forward in various ways. I feel like I still need to integrate these 4 with my current 2, and let’s be realistic, they’ve been exposed at this point as I had introduced dirt from the run in their temp run a couple weeks ago in preparation for the integration.

So questions:

Do I let these 4 grow out a bit longer and introduce them when they’re closer to maturity or does that even matter at this point if they’ve been exposed?

Do I cancel the order for the new girls and just see how this goes? I’m trying to hedge the numbers here knowing we will have a percentage loss and know it will be harder to replace later in the year. But I also feel like I’m sacrificing these girls to the probability gods.

Do I see if I can change the order and switch out the 2 SS to EEs and cross my fingers for hybrid vigor (or will that even matter with Marek’s?). I had really wanted Speckled Sussex girls but now I’m reading they’re super susceptible to Marek’s so that doesn’t seem fair to them. Or do we just move forward and see how it plays out. I do not know if I can change out our order until I speak with someone Monday.

I have baicalin here as I had bought it back when my first girl got sick. I can put everyone on that now as a cross my fingers Hail Mary and see if it helps. @2ndTink gave me a lot of good info about Chinese skullcap earlier this year, so maybe it will help.

We are rural on acreage but are surrounded by other properties full of chickens, plus the abundant wild bird and Turkey population. Mine haven’t free ranged but with the dander and the other farms, I guess none of that matters for this specific virus. Even if I got rid of all of these birds, built a brand new coop and run somewhere else on the property, I expect future exposure will be almost certain.

If you’ve gotten this far, thanks for reading. WWYD?

*i placed here because it’s more about figuring out flock management but if it should be moved to the medical group, please let me know)

 

[CabritaChicks]

I’m so sorry you’ve found yourself in this group, but you’re absolutely not alone. Im writing too much I can already tell because my mind is going 100 times a minute- but I want to be through.

I was just writing a paper on it, so I will summarize:Im sure you know already that Marek’s Disease Virus (MDV) is a highly contagious alphaherpesvirus that causes a range of symptoms, including paralysis, immunosuppression, and tumors (reminds me of PBFD in parrots). The virus is extremely persistent in the environment—shed via feather dander and capable of surviving in dust and bedding for months, even years under the right conditions.

• Latency period: Clinical symptoms often appear 3–25 weeks post-infection, depending on strain virulence and bird susceptibility.
• Vaccination: The Marek’s vaccine (usually CVI988/Rispens) does not prevent infection or transmission, but does reduce tumor formation and mortality (like the covid vaccine), especially when chicks are vaccinated within the first day or two of life and isolated from wild virus for 2+ weeks. But check what you are feeding- are you substantially supporting their immune system? Immune system plays a HUGE part as to whether the bird will be a-symptomatic, or fall short of the cards.
• Environmental risk: MDV can be carried in dander, clothing, or equipment. Once endemic on a property, it’s complicated to eliminate completely. But that is what they said about PBFD in clinic- and we used 'bombs' to eliminate it, plus sprays. There was zero trace afterwards.Your Questions:
  • Should you wait to integrate?
    Unfortunately, exposure has likely already occurred due to the dirt introduction. At this point, your goal is to support immune resilience and reduce stress. Letting the younger birds grow a bit may help slightly (older birds tend to fare better), but it's not a guaranteed advantage. Focus instead on minimizing overcrowding and stress when you do integrate.
  • Cancel the new order?
    That’s personal, I would. Many choose to continue—knowing losses may happen—but that a vaccinated, genetically diverse, and stress-minimized flock can still thrive. Dedicated cleaning of the soil, and coop may require time. If you’re emotionally and financially prepared for the possibility of losses but want to keep moving forward, it’s okay to proceed.
  • Breed selection (EEs vs SS)?
    You’re right: Speckled Sussex are often reported anecdotally as more Marek’s-susceptible. Easter Eggers tend to have hybrid vigor and seem to show stronger resistance in many mixed flocks. While it’s no guarantee, switching to more robust breeds may tip the odds in your favor.
  • Use of Baicalin (Chinese skullcap)?
    Preliminary research shows that baicalin has antiviral, anti-inflammatory, and even possible anticancer properties. Some poultry keepers report success using it as a supplement to support immune response. It won’t cure Marek’s, but as a “Hail Mary,” it may provide some supportive benefit—just ensure Here’s a list of steps you can take right now:

• Clean with F10: F10SC Veterinary Disinfectant has proven efficacy against MDV. Use it to clean all coops, feeders, and tools. It's safe for birds and very effective against enveloped viruses like Marek’s.
• Keep air clean: MDV travels in feather dander. Good ventilation reduces airborne viral load. If practical, HEPA-filtered air or outdoor housing with excellent airflow can help.
• Future chicks: Consider isolating vaccinated chicks for the first 2–3 weeks after hatch before exposing them to older birds or the coop.

You're clearly dedicated, thoughtful, and doing everything in your power to give these birds the best possible shot. That matters. Keep going. There is a path forward, and you're not walking it alone.

 

[2ndTink]

Here are my opinions and what I've done, all based on my experience with the strain I have in my flock and how it has impacted the specific chickens I have, so your results may vary.

Do I let these 4 grow out a bit longer and introduce them when they’re closer to maturity or does that even matter at this point if they’ve been exposed?

If they are on the same property outside and you've worn the same clothes / shoes between them, then from a virus perspective it doesn't really matter. From an ease of integration, sometimes they do best when they are all about the same physical size.

You can look at your setup and see if you think the way they are now has the new pullets in a situation where the viral load may be lower than in your main coop. You can also clean your main coop really well and douse it with a sanitizer, there is one, activated Oxine, that I've read people even spray their soil with it to help disable Mareks virus in the ground.

If you've been back and forth between coops, then yes they have been exposed, integrate when you are ready.

Do I cancel the order for the new girls and just see how this goes? I’m trying to hedge the numbers here knowing we will have a percentage loss and know it will be harder to replace later in the year. But I also feel like I’m sacrificing these girls to the probability gods.

I understand this! I debated this a lot too, but I found vaccination worked very well for me. If you can, pick a room in your house that you can turn into a quarantine area for chicks (I'm assuming day olds? If they are older, disregard!) keep them in quarantine for at least 2 weeks, I shoot for 5- 6 before putting mine outside.

Do I see if I can change the order and switch out the 2 SS to EEs and cross my fingers for hybrid vigor (or will that even matter with Marek’s?).

I have lost 1 unvaccinated hatchery EE, 1 is still around, and the vaccinated hatchery EE's are 4 years old and going strong. I've never had SS, but I do have silkies and the vaccinated ones I have not had any issues with. This is a tough question whether to cancel the order, leave as-is, or change the breed. The extremely hard part is, we just don't know. We can't even make good educated guesses on which scenario will end with no, or minimum losses. This is going to come down to how much risk are you willing to take and no one other than you can answer that. Even if you didn't have Mareks in your flock, there are still a million things a chicken can and will die from. This is not an excuse to throw caution to the wind, but a reality. My friends with chickens who don't have Mareks had almost as much loss for various reasons in their flocks as I did.

I have baicalin here as I had bought it back when my first girl got sick. I can put everyone on that now as a cross my fingers Hail Mary and see if it helps.

I would put them on the double preventative dose, after 3 weeks it is supposed to stop the shedding of new virus into the environment by your existing flock. Since starting my flock on baicalin last fall I haven't had any new symptomatic Mareks cases.

We are rural on acreage but are surrounded by other properties full of chickens, plus the abundant wild bird and Turkey population. Mine haven’t free ranged but with the dander and the other farms, I guess none of that matters for this specific virus. Even if I got rid of all of these birds, built a brand new coop and run somewhere else on the property, I expect future exposure will be almost certain.

Correct. They say Mareks can be carried on the wind for 5 miles, it survives for weeks or months on surfaces, and under I think it was 38 deg it lasts forever.

 

[2ndTink]

You're clearly dedicated, thoughtful, and doing everything in your power to give these birds the best possible shot. That matters. Keep going. There is a path forward, and you're not walking it alone.

Perfectly said! Thank you!!!

 

[townchicks]

A lot of folks on here manage flocks that have a viral load of one form or another, inc. Mareks. Most go with vaccinated chicks or pullets, knowing that there will be some loss. Only you can decide if that is acceptable to you. The way I look at.it, there are so many different ways for chickens to die, that are completely unpreventable. The only thing we can do, is try to control what we can. The Mareks vaccine is one way to mitigate some of those deaths. Even the worst of us "backyard" chicken keepers probably provide a much better quality of life than any commercial operation, and if you think you can do that, and it sounds like you do, then I think it is reasonable to add more to your flock. A short, happy life, and a quick, merciful death, if symptoms arise, sounds better to me. A word about "hybrid vigor" , that's not really something that occurs in hatchery chickens. Hybrid vigor occurs when chickens, or dogs or whatever, randomly breed for multiple generations, and the weaker individuals die off or are dispatched before they contribute to the gene pool. Simply crossing two, or a few breeds together, does not make hybrid vigor, animals are only as strong as the genes going into them. That's why some people prefer not to vaccinate, and let nature sort out the strongest. I don't advocate for either approach, I don't breed or raise chicks, so I don't have to decide. Anyway, Speckled Sussex are awesome, but so are EEs. Good luck.

 

[CabritaChicks]

A word about "hybrid vigor" , that's not really something that occurs in hatchery chickens.

Apologies—my clinical work is primarily with parrots (though I do treat chickens as well in my mobile vet clinic). That phrase is actually quite common in the parrot world, especially with the rise of so-called “designer” parrots.

It’s interesting because, unlike dogs, cats, or chickens—which are all the same species with different breeds—every parrot is its own distinct species. Yet people still hybridize them to try and get the “best of both,” even across species lines because they have different immune systems, tolerances and even dietary restrictions (its actually quite common now, and no one knows the difference). It’s a bit wild when you think about it—at least dogs, cats, and chickens are staying within their own species!

 

[townchicks]

Apologies—my clinical work is primarily with parrots (though I do treat chickens as well in my mobile vet clinic). That phrase is actually quite common in the parrot world, especially with the rise of so-called “designer” parrots.

It’s interesting because, unlike dogs, cats, or chickens—which are all the same species with different breeds—every parrot is its own distinct species. Yet people still hybridize them to try and get the “best of both,” even across species lines because they have different immune systems, tolerances and even dietary restrictions (its actually quite common now, and no one knows the difference). It’s a bit wild when you think about it—at least dogs, cats, and chickens are staying within their own species!

No apologies needed, IMO, that is the correct usage of the term hybrid, as in cross species. Here in the US, it has increasingly come to be used to describe the so called "designer breeds" like labradoodles, for instance. I think it's really meant to make them seem more special and exotic, so people pay big money for what is essentially a mongrel that you used to get for free. When I was young, the term hybrid vigor was applied to random bred mongrels, that were supposed to be more healthy than "inbred" purebred dogs. Bottom line, dogs are all dogs and chickens are all chickens, and prone to all the same issues, unless the breeder is specifically screening and working towards eliminating health issues. Hatcheries are breeding to make money, not Mareks resistant chickens. Apologies to @Closing Time for hijacking your thread for my soapbox.

 

[Closing Time]

Omgosh! You guys really came through to provide some amazing insight and help me take a breath and work on our path forward. I was pretty distraught after reading the report yesterday and was hesitant to even post. But now I’m glad I did.

Thank you @CabritaChicks, @2ndTink, and @townchicks (also, thanks for clarifying regarding the hybrid vigor of hatchery chicks!) appreciate all of your suggestions and you’ve given me a lot to think about.

I clean the poop board and the walk-in coop daily, the run I clean every day or every other day. I’m fastidious about cleaning since the current coop is right next to my barn and I try to mitigate as best I can for fly control. It also allows me to know instantly if there is a change in their droppings.

Regarding nutritional/health support, the pullets are still on medicated crumble 20% and I was going to be transitioning them soon over to the Nutrena All Flock 20% that I feed my adult birds. The adult birds just had a round of poultry cell in their water as a follow up to deworming them with Moxivet (after seeing report of tapeworm in the initial necropsy report I received before the final one yesterday). The littles had rooster booster vitamin and electrolytes in a secondary waterer in their set up since we had an unusually warm day for us yesterday. I supplement with vitamin support as needed, but it sounds like I should make it a regular treatment, once or twice a week to give their immune system a boost.

I started everyone today on preventative double dose of the biacalin as suggested, will continue that for the next 3 weeks and then see where if I should continue at the level or drop down to regular preventative.

Wondering if anyone has used sodium butyrate successfully with their Marek’s flock? I saw it was listed on Poultry DVM and then read some studies, including the attached white paper. It seems promising but I didn’t get any hits when I searched the forum for it. If so, what form and dose did you use and did you see any good outcomes? It looks like I can buy 600mg tabs at Walmart. The papers I read sounded like it should be a given to add to boost immune health and attempt to stave off the lymphoma, but I’m not sure of long term impacts or deficiencies that it may/may not impart on the GI system.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10932986/


I have Vircon-S that I have used to decon as needed in areas that aren’t currently in use but I’ll be ordering the F10S or Oxine since I can douse the coop and run since it’s safer to use and have the chickens enter the space immediately after treatment. Thank you for the recommendation.

Since the visceral form is what presented in my two girls, I’m assuming that is what we will be dealing with here, or can it also manifest in one of the different forms in this flock (assuming there is no other exposure to any other strains, of course)? I feel like these questions may now be in the wrong forum—apologies.

Perspective is everything and always so much clearer in the bright light of day. You all are right. There are a million things out there gunning for our chickens. At least in this case, I am now aware it’s here and can be mindful of any presentations and assume first it’s most likely the Marek’s. Horses before zebras and all.

We will just carry on then, put in some mitigating measures the best we can and hope for the best. If I can’t change the order for the newer girls, then I’ll pump them full of supplements and give them a good life while they are here.

Thanks again and a quick pic of my lap warmer, Mrs Gladys Kravitz. She’s one of my new girls growing out in my temporary horse trailer coop.

 

[CabritaChicks]

Thanks!
I would also go the good old fashion way for immune support. Make some fermented feed, and when serving throw in finely chopped fresh fruit and vegetables (you can even buy pre-chopped frozen bags and toss in the frozen pieces for the chickens to cool off).

Whole foods are a fantastic choice IMO, here's why, from a scientific and nutritional perspective:

1. Bioavailability​

• Nutrients in whole foods are typically more bioavailable, meaning the body can absorb and use them more efficiently.
• Many vitamins in synthetic form (like some B vitamins or vitamin E as dl-alpha-tocopherol) are not absorbed as well as their natural counterparts.

2. Synergistic Compounds​

• Whole foods contain complex combinations of vitamins, minerals, antioxidants, enzymes, and phytonutrients that work synergistically—enhancing each other’s function.
• For instance, leafy greens like kale provide not just calcium, but also vitamin K, magnesium, and phytonutrients that help the body absorb and utilize minerals efficiently.

3. Risk of Imbalance or Overdose with Multivitamins​

• Multivitamins can easily exceed safe upper limits, especially for fat-soluble vitamins (A, D, E, K), iron, or selenium.
• In animals like parrots and chickens, synthetic vitamins can accumulate or cause imbalances, especially if you're already feeding a fortified diet or commercial feed.
• Especially with fat-soluble ones like vitamins A and D3, which can accumulate and cause liver damage, tissue calcification, or kidney failure.

4. Whole Foods Support Gut Health​

• Natural foods also support the gut microbiome with prebiotic fibers and non-vitamin nutrients that commcerial mixes don’t provide.
• In birds, for instance, foods like fresh greens, sprouted grains, and vegetables help maintain crop health and digestion in ways a vitamin powder can’t replicate.

Cleaning:
F10 comes in two forms- the green bottle (with suds that needs to be rinsed) and the yellow bottle- which doesn't need to be rinsed! Just spray and walk away. Definitely get the concentrate

Hang in there!

 

[2ndTink]

I started everyone today on preventative double dose of the biacalin as suggested, will continue that for the next 3 weeks and then see where if I should continue at the level or drop down to regular preventative.

My recommendation is to keep them on the 2x dose indefinitely. The 1x dose is the minimum dose that they have seen to be effective in studies. In our real world, we don't know that each chicken has eaten exactly that, so if you do 2x hopefully each chicken is getting at least the 1x dose at that point. If you are direct dosing each chicken would be different, but if you mix it in their dry feed or add it to treats, 2x will make sure they are getting what they need.

From the current information, it takes 3 weeks on the CS/B to stop the virus from shedding, but only 3 days being off of CS/B for it to no longer provide protection. So daily dosing is really critical long term. It also has shown effectiveness against HPAI, so some people during the migration seasons bump the dosage to 3x or 4x.

Wondering if anyone has used sodium butyrate successfully with their Marek’s flock? I saw it was listed on Poultry DVM and then read some studies, including the attached white paper. It seems promising but I didn’t get any hits when I searched the forum for it. If so, what form and dose did you use and did you see any good outcomes? It looks like I can buy 600mg tabs at Walmart. The papers I read sounded like it should be a given to add to boost immune health and attempt to stave off the lymphoma, but I’m not sure of long term impacts or deficiencies that it may/may not impart on the GI system.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10932986/

I haven't looked in to that, thanks for the link that is really interesting!

Since the visceral form is what presented in my two girls, I’m assuming that is what we will be dealing with here, or can it also manifest in one of the different forms in this flock (assuming there is no other exposure to any other strains, of course)? I feel like these questions may now be in the wrong forum—apologies.

From what I've read these are different strains, so if your strain is the visceral form, you won't see the typical symptoms for the other strains. I'm sure it isn't impossible to have more than one strain in the flock, but 1 is more than enough!

Perspective is everything and always so much clearer in the bright light of day. You all are right. There are a million things out there gunning for our chickens. At least in this case, I am now aware it’s here and can be mindful of any presentations and assume first it’s most likely the Marek’s. Horses before zebras and all.

Yes, you will recognize issues starting sooner now and there have been people having success helping birds recover from an active Mareks infection.

We will just carry on then, put in some mitigating measures the best we can and hope for the best. If I can’t change the order for the newer girls, then I’ll pump them full of supplements and give them a good life while they are here.

Preventative measures, a healthy diet and lifestyle, love and care, that's a lot more than the majority of chickens in the US get (think commercial barns!). You are doing all you can for your flock and that means a lot to them!