I was looking for a source for more Marek's vaccine, when I found this site. I've always wondered if it was possible to vaccinate a chick later than the first day after hatching....apparently it is. Which is good, because they only sell the vaccine in 1000 dose or higher bottles and you can't store it once it is mixed. I am having a staggered hatch, four days apart, and I only have one bottle on hand.
http://www.firststatevetsupply.com/poultry-health/mareks-disease.html
Interesting Marek's Disease information.
Interesting info Catsy, thanks. Hay.
I find it odd that the only experience that I have had with Marek's disease has been a couple of individual cases. It sounds as if it should be contagious enough to occur in epidemics... (?) Although I isolated the sick birds, it wasn't until they showed signs of paralysis which is well into the infection. I also did not disinfect the premises as recommended. Also the victims had been vaccinated, but as the article stated, it did not prevent the disease. Hmm...
There are definite differences in breed and strain susceptibility to Marek's, porkpal.
I've had chicks from mixed hatches where almost all of one breed (e.g. Salmon Faverolle) came down with it and none of the others did--even though they had been together in the same brooder their whole lives. I've also had cases of very mild transient paralysis where I was out back digging their little graves only to have them recover completely. Right now I seem to have a relatively mild strain that pops up here and there. Out of two sets of Cochins, one blue and one laced--all the laced have come down with it and none of the blue.
According to one paper I read there is genetic resistance to Marek's in some lines that can be identified with a blood test...
I am just going to vaccinate everything and hope for the best.
It is true that only my Jersey Giants have ever been affected, but I've never had any recover from the paralytic stage.
I didn't either for the first two years...then about a year ago I had a Serama that was badly affected but recovered. She is my best pullet now.
Since then I have had three more Serama come down with it and recover. I thought maybe these Serama were just highly tolerant of the virus...but then I had one out of four RIRs become paralytic....and recover completely.
I realize they are now carriers--but so are any chickens that have been vaccinated. I think I may actually have an attenuated strain of the virus. You also really never know how many of your birds were sub-clinically infected.
And I just learned that chicks raised by a broody rarely come down with Marek's. I don't know if this is because the broody keeps moving them around, so they aren't overwhelmed and have time to build up natural immunity--or if there is something about being with a broody that affects their immune system.
Right now I am becoming paranoid about feather dust near chicks--since that is how the virus is transmitted. I think breeding for resistance should be a priority.
All the Marek's deaths I have had were among young Jersey Giant pullets between six months and a year old. I had Barred Rocks and Buff Orpingtons sharing the same coop on each occasion with no signs of infection; plus other Jersey Giants, some that were younger, some the same age. I hate not really knowing what is going on with my animals. Clearly any Marek's that is here is a virulent form. Can a carrier be reactivated under certain conditions as with the mammalian herpes viruses I wonder?
Yes, they do say that a latent infection can become symptomatic when a chicken is under stress--the example most often given is when a pullet first begins to lay.
I haven't had that happen. All my infected animals showed symptoms at about 5 weeks, just as their juvenile feathers come it and the immunity from their mothers wears off.
Here is a good site for more information--especially the section about half way down called "If Your Bird Breaths It Has Been Exposed to Marek's."
http://fowlfacts.proboards.com/index.cgi?board=disease&action=display&thread=126
This message was edited Feb 16, 2010 3:04 AM
So often I've heard someone insist their bird was injured.. it stumbles and can't get around.. then it recovers. The owners are convinced a hip was dislocated or it was injured. I'm pretty sure it was Marek's.
I know the pain of having a pullet start laying only to die shortly after..
Thank you Catsy for posting your findings..
I have never had my chickens vaccinated for mareks and have had no outbreaks,I was going to get some chicks from macmarrray should I have them vaccinated at the hatchery or not bother.All my chickens were from hatcherys except my silkies.What is your opinun?
I wouldn't, if you already have unvaccinated chickens.
A chicken that has been vaccinated does shed virus...meaning that although it is healthy it is harbouring the virus and can theoretically transmit it to unvaccinated chickens who may become ill. Once you have the virus in your environment it is very likely to persist and become a problem for new unvaccinated chickens. Silkies and, in my experience, Cochins are particularly susceptible.
Marek's is difficult to deal with because it is transmitted by the feather "dust" that chickens constantly shed and which can easily be carried long distances on the wind. Also, some wild birds can carry the virus and transmit it to your chickens.
Chickens are believed to become resistant to Marek's as they age--five months usually given as the cut off point for acquiring new infections. Chickens that suddenly show symptoms at an older age were probably infected when they were younger and have had a latent (unsymptomatic) infection that became active when they were under stress.
High levels of virus (a lot of feather dust in the coop or brooder) may also overcome the immune system of some chickens that might otherwise have been able to resist it. That is one of the reasons it is important to keep young chicks away from older birds.
One exceptions seems to be chicks that are being raised by a broody. For some reason being raised by their mother seems to give chicks some degree of protection from the virus. I had three bantams that were raised by their mother in an area that I know has a high level of feather dust from chickens that were exposed to Marek's...they are now 3 months old and so far none show any sign of being infected.
Oh thank you so much because I was going to have that done.Hope I never have to deal with that or any other disease