What is the "true" deal with Marek's???


Sees Wine Dots
10 Years
Mar 22, 2009
Heuvelton, NY
Ok, so here's my story. As I understand it Marek's is pretty much endemic in all flocks, some present and some don't. I started with all hatchery birds. Some from Ideal and some from TSC (My Healthy). None were vaccinated. The big birds because I'm not fond of vaccines in general and have my own views on that I won't get into and the bantams from Mt. Healthy as I understand they don't vaccinate banties. I had added 2 birds into the flock, quaruntined for a month. The hen (polish-vaulted/ameraucana) died within 2 weeks. I did not have a necropsy done, but her symptoms were what I would guess were Marek's or Marek's like. This was in August.
Other than a roo that tangled with my compost pile that I saved from Botulism, I had no disease, death, issues like that one, until Christmas when my Porcelain D'uccle hen seized and died, then my d'uccle roo developed bilateral leg paralysis (both were 8 months old). No wing involvement, no eye involvement, no neck involvement and one heck of an appetite until almost the end when he simply stopped eating or drinking. He oddly also never crowed. Necropsy revealed absolutely no tumours, viscera well intact no internal/crop/nerve issues and absolutely no tumors. I have not had a single standard get so much as even sick and they are all housed in the same building. So, my question is this. If Marek's IS so endemic in chickens and vaccination essentially a way to decrease mortality and not really the disease itself, should I have a closed flock? I know eggs are not susceptible. If I breed and sell hatching eggs and by some chance Marek's is in my chickens do I put anyone elses flock at risk. I would NEVER want to run the risk of harm to anyones birds. I thank any of our well knowledged members that may be of help. This is more of an ethical dilema thing for me.
Sorry you lost your roo. Mine was 2 years old and it looks like he died from Mareks. I have 22+ chickens and he was the only one. I have mostly my own hatched chickens. It seems to me that if he got it, it may be that his immune system wasn't the best. Early last year he was too the only one who got coccidiosis.

From what I gather, vaccinated birds are still carriers, they just won't get tumors. Most unvaccinated chickens have immunity to it after 4 months old. Most, not all. The vaccine is to prevent chicks from dying from it.

My roo did not have tumors either. The paralysis started in his legs, then to his wings, and he could not control the movement of his neck enough to eat. All thru this he was crowing in the morning, and looked happy. It was heartbreaking.

If you add a chicken to your flock, whether it is vaccinated or not, it can still carry Mareks. If you hatch eggs, the chicks can get it if you have it, but can't carry it in from a hatched egg.

My roo could have gotten Mareks from an infected wild bird, from the neighbor's coop next door, or from the one adult I added, a silkie pullet who was quaranteened for 30 days and never sick. The roo was a silkie, I have 4 more that were with him, and one of them has hatched 4 chicks, which are in with them. Whether I would have vaccinated them or not, they would have been exposed first since they were hatched under mom. The vaccine has to be given 10 days before exposure to other chickens.

Sooo, if you add chicks, or hatch eggs, they have to be vaccinated 10 days prior to being exposed to your flock, since a few of yours have died from what looks like Mareks. If you sell eggs, the eggs can't carry it. If you sell chicks, whether they are vaccinated or not, they can carry it. If it's so prevalent, I don't see how anyone can buy or sell chicks without ever coming in contact with it. And once the youngsters are over 4 months old, they do have some immunity to it.
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Necropsy on the latest death (last week) showed no tumors or signs of mareks? Bizarre. I have no idea, I just know I don't want to hurt anyones flocks. That's my real fear.
If they have the one on the nerves, you may not see tumors.
My silkie roo was staggering one day. The next day, he couldn't walk. I put him in a crate on my patio. Within a few days, one wing was down, one helped him stay upright. One forward, one leg back. And his left eye just got smaller and mishapen, and had no sight. He lost control of his neck, he could not aim, and rather than tube feed him, I had the vet euthanize him. The vet said he didn't see any tumors, so his opinion was that the silkie had Eastern equine encephalitis, which is possible in Florida. But he still had classic Marek's signs.
Nope this one had bilateral leg issues, but use of both wings, no eye issues, no eating issues, no neck issues and no tumors. He was also "picked on" by a very large roo.

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