Flock has MG and M. Synoviae

[PipeWelder56]

Got 40 new chicks from rural king back in February to ada to our 15 hens of 3 years. Out of the 40, 28 made it longer than a week. Within the last 2 months we've had 8 more pass. Sent the last one off for a necropsy and got the results today and she tested positive for MG and M.Synoviae. What should we do going forward? Cull the whole flock? If we do cull will it be safe to eat the meat?
What would we need to do to the coop to be able to house new chicks? We don’t sell our eggs or anything but also don’t wanna be without eggs for months. Just looking for advice. Thanks.

 

[Sally PB]

Tagging the experts.
@azygous
@Wyorp Rock
@Eggcessive

 

[Eggcessive]

Welcome to BYC. So sorry that your flock is MG and MS positive. That is really tough. Have you treated the symptomatic ones with any antibiotics? MG is fairly easy to treat with Tylosin or Denagard and a few others, but MS is hard to treat. That said, only some of the birds may get symptoms. All should be considered carriers, and never re-homed, but some may never get the symptoms.

It is up to you whether or not to depopulate and start over. But MG and MS is present in wild birds, and the new chicks could have gotten it from them or even one of your older birds. Many people have MG positive flocks, more than MS. I would either treat any sick birds or cull those. The eggs are fine to eat, and the meat is fine unless there are secondary infections or the meat just doesn’t look right. You could see how it goes through the next winter, and then decide one way or another whether or not to cull all birds. There is no guarantee that a new set of chicks wouldn’t get it from wild or migrating birds. Personally, I wouldn’t, but I might cull very sick birds. Here is a very good article others have recently posted here which is full of facts about mycoplasma:
https://ccmedia.fdacs.gov/content/download/77376/file/Mycoplasma-Brochure.pdf

 

[PipeWelder56]

Welcome to BYC. So sorry that your flock is MG and MS positive. That is really tough. Have you treated the symptomatic ones with any antibiotics? MG is fairly easy to treat with Tylosin or Denagard and a few others, but MS is hard to treat. That said, only some of the birds may get symptoms. All should be considered carriers, and never re-homed, but some may never get the symptoms.

It is up to you whether or not to depopulate and start over. But MG and MS is present in wild birds, and the new chicks could have gotten it from them or even one of your older birds. Many people have MG positive flocks, more than MS. I would either treat any sick birds or cull those. The eggs are fine to eat, and the meat is fine unless there are secondary infections or the meat just doesn’t look right. You could see how it goes through the next winter, and then decide one way or another whether or not to cull all birds. There is no guarantee that a new set of chicks wouldn’t get it from wild or migrating birds. Personally, I wouldn’t, but I might cull very sick birds. Here is a very good article others have recently posted here which is full of facts about mycoplasma:
https://ccmedia.fdacs.gov/content/download/77376/file/Mycoplasma-Brochure.pdf

We’ve decided to just let it run its course and cull the ones that show symptoms. We just got the results back today so no antibiotics yet. If we vaccinate new chicks for mg and ms can we bring new chicks in or is it still going to be a chance they get it? And I’ve also read different things about time before adding new birds back to the coop. Some say 2-5 days after the last bird is gone and some people say give it a few months. Any input on that? Thanks for everything

 

[Perris]

In addition to what others have said, and what's in the pdf linked last post, you could also treasure and breed from the birds in your flock that survive, without medication, since those birds thereby demonstrate that they have a strong innate or acquired immunity to the MG and MS strains on your property.

Many flocks have MG and/or MS without the keeper being aware of it, because these infections are endemic and widespread, and the symptoms are often subclinical or invisible; that is not so in your case, as the recent chicks casualties show. But your older hens are probably immune, and some of the chicks may be too, despite being hatchery products raised in a sterile environment (which is what makes them particularly vulnerable to any infections they meet in the environment now). Innate immunity can be passed on to offspring, if such birds are allowed to live and breed, instead of being culled.