Yesterday when I opened up the coop I noticed my speckled sussex hanging back a bit. After a minute or so she kind of tumbled out. She couldn't stand up and kept falling over to her right side and throwing her right wing out to catch herself. I put her in front of her food and she ate, then I put her in front of her water, and she drank. I left her there, and when I came back out to check on her a few hours later she was across the run, sitting by herself next to the fence. I picked her up to look at her legs and wings, all seemed normal, nothing obviously out of place or broken. I watched her throughout the day. She could walk, but she looked like she was drunk. At dusk they all put themselves in the coop like usual, she was the last one in, it took her a few tries, but she made it. The door is 6-8 inches off the ground, no ramp. After talking with the friend I got all my chicks from, I went and got her out of the coop and brought her inside. The chicks were not vaccinated against Marek's as there was a vaccine shortage this year. She is in a kitty carrier with food and water. The water has ACV and crushed garlic in it. Her poop is normal, no blood. The food is not moldy. She has no obvious mites. I don't feel any lumps anywhere on her. Her eyes are normal. She is not gasping. She does not feel emaciated. She was pretty lethargic this morning but is more alert again. Still eating and drinking normally. She isn't doing the splits, but she does lay on her side with one leg extended and one retracted. She can move both legs and she can flop around, but she still can't stand up and flying is out of the question. The rest of my flock seems fine. I have 5 other birds, and I have been able to catch all but 2 of them and checked them for lumps also. I can't feel any, but then again I have no experience with this so I could be missing something since I don't have a baseline for what the body of a healthy chicken feels like. There is a tall spruce in the middle of the run, so it is quite easy for all the wild birds in the area to get into the run/coop/food. I know that the only way to know for sure if it is Marek's is to have her tested if/when she dies, but I have no idea where I'd send her or how much it costs. I cleaned out the coop, but I'm sure it's too late for my others if it really is Marek's. I guess it's just a question of if they will be affected or if they will just become healthy carriers. Anybody with experience care to weigh in?