Ron,
This question isn't about Bresse, but about Marek's and really doesn't belong here.....but I am going to ask anyway. I have a really large Kennel Cage(my Pyr will fit in it) that we repurposed with some modifications into a recovery pen for my newly caponized cockerels. Unfortunately because of space issues, they stayed in there longer than I wanted. Anyway, when I moved them, I discovered one that was falling off to left side, but was not paralyzed on that side. It was hard to tell if he was weak or having balance issues or had been injured because of the close quarters. I went ahead and put him back into this kennel by himself. He could keep himself upright, but his head kinda bobbed like he was trying to keep his balance. He continued to show some weakness or balance issues, but ate grew and gradually got better. He goes in and out of the pen now, flaps his wings, and seems perfectly fine. I haven't integrated him with anybody else because I wasn't sure if he had had something contagious(though none of the others ever had any symptoms) and I also didn't want him getting picked on. Also, he is a capon slip but isn't crowing, so I knew his further existence would be short. What I am wondering is if you think he had Marek's, albeit mild. Also, there wouldn't be any reason not to process and eat him even if he has had Marek's?
Yes, I think he had mareks. You can eat him. All of your chickens have had mareks. They just did not show the symptoms. Even the ones that show symptoms usually recover if you make sure they are eating and drinking.
Just to be sure, keep him quarantined for two weeks. If all of them are ok, then it is not spreading through the flock and he can go back with the others.