Which breeds are most and least susceptible to marek's

[Caddyman]

Had a necropsy done on a hen I had to put down recently, it came back that she died from cocci, but also had marek's. My other hens are acting fine, so I've accepted that I will have to have a closed flock now.

When I go to replace my layers next year, the new chicks will be exposed to the Marek's. I'm hoping to find out which breeds are most susceptible and which are most resistant to Marek's so I can give the new chickens the best chance.

Here's what I've seen so far

Most Susceptible:
Silkies
Sebrights

Less Susceptible / More Resistant:
Egyptians Fayoumis
White Leghorns* [edited on 11/6/15]


Any advice on breeds or best practices (maybe buy vaccinated chicks)?

*From a random internet comment "For working on susceptibility - some research states that the B21 gene may indicate some resistance. white leghorns are supposedly more resistant than RIRs and since most sexlinks contain RIR genetics, they are some of the ones that have vulnerability. "

I know it's been over a year but was wondering if you have any updates you could share.
We are dealing with the same exact situation as yours. One of our flock got sick and couldn't stand, walk or really eat or drink. I culled it a day or so later, it was a Sizzle (frizzle silky) and was around 4 months old, a week later we had a Polish that was about 6 months old die suddenly within a week of the Sizzle. We had the Polish tested at UC Davis and they performed a full Necropsy, the Polish came back positive for Marek's disease. Now for the last few weeks the rest of our flock (8) seem healthy, happy and starting to lay eggs.
I had heard from a few sources that Polish and Silky's were both susceptible for Marek's and those were the only two we had of that breed. the rest of our flock consists of 2 Orpingtons, 1 Ameraucana, 1 D'uccle, 3 Bantam Cochin's, 1 Maran and all seem active and healthy.

 

[Folly's place]

Buying replacement chicks that are vaccinated against Marek's disease, and raising them in total isolation from your flock and facility for about three weeks, is the best plan, IMO.
I'd avoid Silkies and Polish in the future too.
If you aren't trying to 'breed for resistance', that's fine, then get only vaccinated chicks.
Keep a closed flock, and restrict visitors to it, and remember that the virus spreads in dust and dander.
So sorry that you have this problem!
Mary

 

[Caddyman]

Buying replacement chicks that are vaccinated against Marek's disease, and raising them in total isolation from your flock and facility for about three weeks, is the best plan, IMO.
I'd avoid Silkies and Polish in the future too.
If you aren't trying to 'breed for resistance', that's fine, then get only vaccinated chicks.
Keep a closed flock, and restrict visitors to it, and remember that the virus spreads in dust and dander.
So sorry that you have this problem!
Mary

The funny thing is the Polish was the only one we got that was vaccinated as a day old chick?
From my understanding (and I could be wrong) 7-8 month old and older chicken won't show signs of the disease but can be a carrier, just won't affect them. The rest of my flock is currently 6-8 months old I figured I would be better off getting started pullets vs. raising chicks again?
Thanks for you help!
Dwain

 

[Folly's place]

About your Polish; did you have her as a chick? Was she isolated from your property for three weeks after vaccination? Was Marek's disease the cause of death?
Chickens can die of Marek's disease later, and older pullets won't be safe unless the have Marek's vaccine on board as chicks. The vaccine tends to prevent the tumors, not infection. All the birds you have are infected, but all won't die of it.
Mary

 

[Caddyman]

She was hatch last July, I got her as a solo chick from a local breeder that vaccinates her day old chicks. When I got her she was 17 days old. She was with two other chicks when I got her and all three were under a heat lamp but the other two I don't have anymore because they were Roo's (Brabanter and a Frizzle Cochin). Cause of death was Multiple organs failure.
Dwain

 

[oldhenlikesdogs]

Vaccinated birds should not be mixed with non-vaccinated as they can shed the virus their whole life but never come down with it.

I prefer non vaccinated, and cull any that show symptoms. I've seen it more in my bantams than my standards. Out of about 80-90 birds I will see 0-2 a year in a batch of chicks showing symptoms. The rest are fine. I do keep turkeys so they may provide some immunity.

 

[Folly's place]

To clear up any confusion; vaccinated birds do not shed the virus because they are vaccinated! They will shed virus if they are exposed to actual infection and become infected with Marek's disease. They are then very unlikely to develop the tumors caused by Marek's, so should be healthy, and if invited into an uninfected and unvaccinated flock, will shed virus.
Nothing is more important than practicing good biosecurity! If your flock does become infected and you want to raise your own chicks, breed your healthiest individuals to each other each generation, and keep a closed flock. Or, if you plan on buying replacement chicks, have them vaccinated and isolated away from your environment for three weeks so they will have immunity.
Mary

 

[Caddyman]

To clear up any confusion; vaccinated birds do not shed the virus because they are vaccinated! They will shed virus if they are exposed to actual infection and become infected with Marek's disease. They are then very unlikely to develop the tumors caused by Marek's, so should be healthy, and if invited into an uninfected and unvaccinated flock, will shed virus.
Nothing is more important than practicing good biosecurity! If your flock does become infected and you want to raise your own chicks, breed your healthiest individuals to each other each generation, and keep a closed flock. Or, if you plan on buying replacement chicks, have them vaccinated and isolated away from your environment for three weeks so they will have immunity.
Mary

I can't have Roosters so I won't be breeding my own, (I remember the birds and the bee's talk I had as a child so I know how it works to get baby chickens) but I do have a couple of questions.......

1) When you say isolated chicks away from my environment for 3 weeks, how far away? Can I keep them in the garage under a heat lamp. The garage is on the other side of my house from our coop. Or do you mean not even on my property?
2) If I buy started pullets that has been vaccinated for Marek's should that be the same as keeping chicks isolated for 3 weeks or so?

We started this project last summer thinking it would be fun to have chickens and with a bonus of fresh eggs. To be honest it's been a pain in the a$$ but now were in it and have to make the best of it. I've been forced to learn more about chickens than I have ever thought I needed or wanted to know. Ok........rant over!

At first when I got the report back from UC Davis I was going to cull the entire flock but was told that some strong chickens can survive Marek's so we I've held off to see what happens. From my understanding Marek's sounds similar to HIV/Aids where you can be infected but not die from it.

Thanks for everyone's help and information!

 

[Folly's place]

The biggest issue with Marek's disease virus is that it can live in the environment for a LONG time, maybe years (ask at your state veterinary poultry lab) so culling your current flock doesn't matter.
You can raise your chicks at home, with good biosecurity. It's difficult at home, because the dust and dander from your birds will spread, and remembering to keep everything totally separate for that time is difficult too.
Started vaccinated pullets could work; again, ask the expert!
Started pullets can be very expensive too.
Many birds don't die of Marek's disease, and IMO just move forward with who you have, and some new chicks this spring.
It's very good that you had that necropsy done! With information, you can have a plan.
All the best, Mary

 

[annagoodspeed]

The first bird to die of Marek's type symptoms here was a Legbar pullet that came vaccinated for Marek's. Since then almost all the Legbars and all but one Welsummer Legbar cross have died of it, but very few others, I think a couple partridge Wyandottes. I have Langshans and they were all fine these past two falls, and all the Paul Smith Ameraucanas are fine, along with the two Svarthonas.
It definitely seems to be a by the breed thing here.
Not a fan of Legbars, but I am smitten with these BBS Ameraucanas.