I have some questions about Marek's disease and Laryngotracheitis and their vaccines.

[ozexpat]

I personally would be worried about mixing those birds in with my flock. I dont know enough to offer you advice though.

I will follow the thread and see what people say.

 

[cochins1088]

I personally would be worried about mixing those birds in with my flock. I dont know enough to offer you advice though.

I will follow the thread and see what people say.

Would you consider it a credible source?



He sells lots of high quality birds on a regular basis and I doubt that everyone he sells too uses the same vaccine. He said that he has never had any problems mixing vaccinated birds with unvaccinated birds.

I'm nervous, but I really want these birds. I sent him an email asking about the specifics of the vaccinations.

 

[cochins1088]

I can narrow down my search. He used the Chicken embryo origin (CEO) vaccine.

It's starting to sound like I'd be better off to find a different breeder...

 

[cochins1088]

From: http://www.jstor.org/discover/10.2307/1591116?uid=2129&uid=2&uid=70&uid=4&sid=21102734702833

Unvaccinated sentinel chickens were maintained in contact with the vaccinated layers during three intervals between 1 day and 6 weeks post-vaccination. Diagnostic tests performed on the sentinels to detect lateral spread of vaccine virus from vaccinated to unvaccinated chickens showed scattered positive results.

 

[Nambroth]

I cannot help you with the Laryngotracheitis question, but I can tell you based on what I have learned about Marek's disease, I would never purchase birds or bring them in from a flock that has had confirmed Marek's within the last decade.

As someone that has had a bird die from this disease, and now my entire flock are 'carriers', I would not wish Marek's on an enemy! There is no cure and it is truly sad to see a bird go through it. Even if I were to breed and vaccinate for resistance in my flock, I would never with a clear conscience sell my birds, even many years from now.

Marek's is a virulent herpesvirus and can live in an environment for years. If this fellow truly had Marek's disease on his property, in his flock, before... he still has it. The only way I can think of that he'd be rid of it is if he culled the flock that had it, completely sanitized every square inch of coop(s), and waited many years before bringing chickens in again. It is shed in the dander of infected birds (even if they do not become symptomatic). It is entirely likely that his birds are still carriers, and never show symptoms because they are vaccinated. They may also have, over the years, built up some natural immunity as well.

You can buy the vaccine and vaccinate your current birds. This may help them, but please be aware that the vaccine is only at its most effective when administered to day-old chicks, so that they can build resistance as they mature. Vaccinating your adult birds now, as an analogy, is NOT the same as vaccinating an adult dog for something like rabies. The vaccine does not cause immunity-- rather, it works with the chick's natural immune system and builds a resistance. This is about 90% effective when HVT (Turkey Marek's) vaccine is administered to day-old chicks, against Marek's. However, there are now mutations of the Marek's virus out there, and so there are a lot more variables at play. HVT is proving somewhat ineffective against some of the other Marek's strains.

In a nutshell:
-The birds from a past Maerk's positive flock are possibly carriers still.
-If you bring in carriers, they will still shed small amounts of live Marek's herpesvirus and it is very contagious.
-Marek's is very virulent and can be 80% or higher lethality in chickens that do not have resistance/immunity.
-You can vaccinate your adult birds and it will not HARM them but it may not help them against Marek's. It is a big risk.

I would personally seek my bantam cochins elsewhere, however the choice is yours! You may not have a single problem, or it could be a nightmare. If you are very set on getting the birds, you might ask some of his past customers and see if they have had any illness or unexplained deaths in their flocks.

I'm not trying to scare you-- I'd just hate for you to knowingly bring this disease home! Once you have it, you are married to it, so to speak.

 

[Nambroth]

If you want to read sometime about some of us with Marek's positive flocks, this is a good thread. https://www.backyardchickens.com/t/741957/not-an-emergency-mareks-in-the-flock

 

[cochins1088]

I messaged Haunted55 (starter of that thread) asking the same questions that were in the initial post of this thread and this was her response:

If your birds now are a year or older, you could vaccinate to be on the safe side, but chances are, they have already been exposed to Marek's in some form. As for the vaccine masking the disease...I'm not so sure of that. Maybe, but if that is true, then it also makes the duration of the time they are infectious less. See, just because a bird has Marek's or been exposed to it doesn't mean that they are shedding virus 24/7. They aren't, what it means is there is a chance that if they get stressed or sick, they could. A lot of people lose sight of this simple fact or never knew it in the first place. A lot of the information out there on Marek's now is extremely outdated and that is why you hear the cry to cull, cull, cull. No reason to at all. Marek's is out there, everywhere. Everyone's birds are exposed to it at some point in their lives.

I value your response and I thank you for replying, but Haunted55's response provides a different view of the situation. She says that virtually all chickens are exposed to it and that some are simply more resistant than others. She says that it wouldn't hurt to vaccinate my older birds, but that it probably won't help any because most likely they have already been exposed.

Again, lots of conflicting information. I guess I'll go do more research on Marek's disease.

 

[Nambroth]

While I agree that Marek's is more common than most people think, and that it can happen to anyone's flock via environmental conditions (such as the wind blowing it in, or it being carried in on wild birds, etc), I will disagree that everyone's birds are exposed to it. Otherwise, everyone that has their birds blood tested for Marek's DNA markers (and these will absolutely will show up in any Marek's+ bird because Marek's creates DNA latency!) would be bound to have some positive markers. I know folks that have tested negative in their flocks, even flocks that have been kept for years.

My point is that I would never intentionally introduce it into my flock. It's a moot point for me, since my flock tests positive for it now, but for someone that has a healthy flock that has never had known exposure? That's a risk I personally would not take. If you chose to, that is up to you! Just go into the decision well-armed with knowledge.

 

[cochins1088]

While I agree that Marek's is more common than most people think, and that it can happen to anyone's flock via environmental conditions (such as the wind blowing it in, or it being carried in on wild birds, etc), I will disagree that everyone's birds are exposed to it. Otherwise, everyone that has their birds blood tested for Marek's DNA markers (and these will absolutely will show up in any Marek's+ bird because Marek's creates DNA latency!) would be bound to have some positive markers. I know folks that have tested negative in their flocks, even flocks that have been kept for years.

My point is that I would never intentionally introduce it into my flock. It's a moot point for me, since my flock tests positive for it now, but for someone that has a healthy flock that has never had known exposure? That's a risk I personally would not take. If you chose to, that is up to you! Just go into the decision well-armed with knowledge.

I'm more than likely not going to buy from this breeder. More so because of the laryngotracheitis vaccine that he used.

I should probably get my flock tested. I wonder if they've already been exposed. When I first started keeping chickens, I didn't practice any bio-security measures. I would buy birds from poultry swaps and wouldn't even give it a second thought.

Now I research breeders before I buy birds and I keep the buying to a minimum.

I'm going to try to find some scientific studies on Marek's disease. I'll be sure to post anything that I find useful.

Thanks again for your responses!

 

[Nambroth]

No problem. I hope I did not come across too strongly-- I just got nervous on your behalf at thinking of intentionally bringing the disease in. There is new information coming out about Marek's all the time, you may find something very interesting! All my best to you! I hope you find another good breeder for your cochins. I love them.