OMG I think it's Marek's - now what? (Long, lots of questions, sorry)

I'm a chicken newbie and very distressed because I'm 99% sure I have Marek's in my little flock. I got 30 EE chicks from a small breeder at Easter this year (I thought they were real Ameraucanas but they're not). At 4/5 weeks a couple of the pullets became suddenly weak with what looked like neurological problems; one of them had a weak neck and the other was unable to stand and just lay on her side for a couple of days. Thinking it was a vitamin deficiency (and maybe it was, but now I wonder), I treated with poly vi sol and they recovered quickly although one of them continued to walk sort of crouched down on her hocks for awhile.

They are now 3 months old. One pullet has been "sleepy" for well over a month; she eats and drinks etc but tends to hang around with her eyes partially closed and neck feathers a little ruffled, and she makes odd little movements with her neck that look like a mild neurological impairment. She stays inside the house all day and never goes out. Sometimes she stands with her head in the corner. Now there's a second pullet hanging out with her and acting the same way.

A month or so ago one of the cockerels became profoundly weak with what I now understand is the classic "Marek's" pose (one leg forward and one leg back). After a few days he was doing so poorly that we culled him and in my blissful ignorance I assumed it was an isolated incident. Two days ago, again between one day and the next, another cockerel came down with similar symptoms, although his legs are mostly kept in front of him (when he's not flopped over on his side). The first day he was able to get up and move around although he was very ataxic, but by the second day although his appetite remained good he was unable to walk. He's a favourite of mine and I was planning on keeping him but he requires hours of nursing each day to get enough fluids etc into him (he drinks eagerly from an eye dropper but won't drink from a water dish). This morning I have two more affected birds: one cockerel that just seems overly tired and is lying down a lot, and another with a paralyzed wing.

I've been up half the night trying to find out what could be wrong with my birds (I was still thinking nutritional deficiency). I'd never heard of Marek's before and this is a real shock. I'm thinking I should just start culling all the symptomatic birds and send one off for a necropsy.

The only place I can think of where they could have contracted the disease is from the breeder where I bought them. There were no chickens here before and the coop is new (still under construction). They were supposed to be day old chicks but due to hatching issues I received some that were a day old and some that were almost a week old, so perhaps the breeder's flock carries the virus and these chicks were exposed before they arrived?

So now I have to figure out what to do next and I'm just sick about it. Some online sources say you should kill the entire flock, disinfect with Oxine, wait a few months (!!!) and start over again. If I were to cull the whole flock and start again next year (horrible thought; I really like my girls and have put countless hours and more money than expected into constructing their coop), would I be overreacting?

Other folks say that it's just something you have to live with, that most if not all back yard flocks have been exposed to Mareks, and that over time the flock will be populated by individuals with more immunity. I understand that birds who get sick and recover will be carriers who continue to shed the virus for years, but what about the ones that don't show obvious symptoms? Surely they've been heavily exposed as well, so shouldn't I assume they're carriers too? I understand some people keep recovered Marek's chickens on purpose to make sure their flock is exposed in order to maintain a resistant flock, but wouldn't it make more sense to just keep the ones that don't get sick? Wouldn't they be the ones with the best resistance? Or is it less transmissible than that and would some individuals in a flock just not contract the virus in the first place? If I keep my flock (and I'm inclined to try), would it mean I can never have a hen raise a brood of chicks, that if I want chicks I'll have to incubate the eggs myself in order to vaccinate, that I can never visit someone with poultry unless I know their flock has been vaccinated, that I can never sell a chicken to anyone else?

I know this is a lot of questions but I'm a little freaked out and could sure use some guidance from those with more experience...

 

Thanks for the replies. According to what I've been reading, vaccination for Marek's doesn't actually confer true immunity so although most vaccinated birds won't develop symptoms, they can still get Marek's and shed the virus as carriers of the disease, which is why many people consider the disease to be ubiquitous and endemic although many people are unaware that their flocks are infected.

That said, if I were to cull all of my birds and start over next year with vaccinated chicks, how would I know that my next set of chickens didn't have Marek's as well? On the other hand, if I keep my girls then I wouldn't be able to sell or give away any birds unless they were going to a farm that was already infected. I really don't want to kill off my little flock, but I also don't want to be forced to kill any culls in the future rather than re-home them. It's a conundrum and I wish I could figure out what to do ...