Adding to a Marek's infected flock?

[MichelleT]

Last year we had a chick that was supposedly vaccinated for Marek's that died. The necropsy showed that the cause of death was Marek's. I have to admit, I have done a LOT of reading on Marek's disease, and I just get more and more confused. I'm not sure if I inadvertantly carried it in or whether my flock had been exposed long ago and no one was affected because of the vaccination. (I adopted my original birds from a farm that rescued organic indstury retirees.) From what I understand, we're now carriers and there's nothing I can do about that. I can, however, practice good biosecurity, to avoid inadvertanly spreading it. In fact, we are ethically bound to do so.

That said, what about adding new chicks? Our vet said to be sure we had vaccinated birds and that they should be separated from the main flock for at least 2 weeks, preferably 3, which we plan to do. Is there anyone out there that has this in their flock and has successfully added new birds? If so, please share what has been successful for you.

 

[sylviethecochin]

We have Marek's. The twelve birds that brought it in originally actually came from a feed store (the chick that showed symptoms healed and grew up to be a cockerel, of course.) Since then, we've had well over a hundred birds. Only two ever showed (detectable) symptoms of Marek's and only one died.

Most flocks in the United States are carriers of the disease--it can spread miles via wild birds, the wind, and your boots. Chances are, the chicks from the feed store were infected by someone who came in to look at them.

Check out this very helpful article for a lot of information.

https://www.backyardchickens.com/articles/the-great-big-giant-mareks-disease-faq.66077/

EDT: And note that the Marek's vaccine is a leaky vaccine. It doesn't prevent the chicks from becoming infected, it just triggers the bird's immune system so that it stops the tumors associated with the disease form forming. It's not even 100% effective.

 

[MichelleT]

Thanks @sylviethecochin... this puts my mind at rest. Now the question is, where to get my next batch of chicks? I just finished reading Facebook comments on the feed store that I got my chicks from and there are LOADS of comments about chicks dying from Marek’s Disease that were bought from this store.

 

[sylviethecochin]

If that's the case, your area may have a particularly bad strain of Marek's. Or perhaps the vaccine wasn't quite as non-infectious as it should have been? (were all of the chicks at the feed store vaccinated?)

I don't believe in vaccination of birds using a leaky vaccine. But I'm not you and I ain't dictating what you should do with your birds. Vaccinate or not as you think would be good for your flock.

That in mind, Marek's does not pass chicken to egg and it's usually not found in day-olds. You could order chicks online from a local hatchery so that they won't have been exposed to quite as much. Or you could just buy hatching eggs from an NPIP-certified farm.

 

[MichelleT]

All of the commenters claimed to have had necropsies done by Colorado State University - where we had ours done as well. (I have the PDF of the necropsy, so I wonder if it has the particular strain... I'll have to dig around in my old email and see.)

One of the posters lost all six of her Black Astraulorps (that's the one we lost). So yes, I think the Marek's came in with this bird, but interestingly enough, none of the other chicks had symptoms of Marek's. One died just prior to POL (from peritonitis of an egg sac that hadn't formed correctly), but the rest made it so far.

I am looking at a local breeder now that does not vaccinate. I have to decide if I want to take that risk or not, I guess. I'll let you know what we decide and what happens...

 

[MichelleT]

So, @sylviethecochin, I know that you said you weren’t telling me what to do, and I appreciate that, but now I am asking: in my position, what WOULD you do? Given my Marek’s contamination history, here are 2 options:
1. I found a local place that sells unvaccinated, 5-week old chicks. The owner has been VERY helpful with answering my questions. Plus the chicks are sexed and if we get a roo, they take it back no charge. She is comfortable selling to me knowing my history.
2. I could order online from somewhere like My Pet Chicken so that I get the Marek’s vaccine included.
3. Just thought of this, but I guess I could do a mix of both...

I’m guessing, given your comment on leaky vaccines, you would go with option 2 and expect some possible deaths.

Thoughts?

 

[sylviethecochin]

I would probably go with option one, actually. But I sell birds and I would not feel comfortable selling a bird that might carry a really dangerous strain of Marek's. Because my birds aren't vaccinated, I know they carry the mild local strain.

If you're keeping a closed flock though, and are careful about biosecurity, option two is probably right for you.

 

[MichelleT]

Sorry, I meant to say you would probably do option 1 . I was right.

Would option 2 be the right choice for me because of the high risk? I assume it’s possible that all the birds from the local breeder could end up fine. Or could end up dead. I just won’t know until it happens....

 

[sylviethecochin]

Yeah, you won't know until it happens. I wouldn't vaccinate, but it's your flock and your decision. You are likely to have casualties because your strain seems to be pretty harsh, but it might happen and it might not.

Truth is, I have no way of knowing, you have no way of knowing, and at this point it comes down to a personal choice.

Whatever you decide, good luck.

 

[MichelleT]

Alright, @sylviethecochin, I'm doing it! I'm going out to the breeder on Monday and getting 6 (non-vaccinated) chicks of various breeds and ages 5 days to 2 weeks old. I'm using the mother hen pad and keeping them inside for a few days, just to keep a watch on them before I put them out. Then they're out in the run, separated and safe from the big girls until it's time to integrate. Do you usually keep your chicks indoors or do you do an in-run brooding? It's how I did my last batch and the integration went so smoothly I swore I would never do it differently. But that was before the Big-M diagnosis so I'm not sure if it really matters - they'll be exposed sooner or later, right? I'm just curious what you do...