Blizz is a three-and-a-half year old red sexlink. I don't know which hybrid she is (ISA brown, golden comet, etc.). I don't know her weight exactly, but it was normal for her until today, at which point she began feeling light. Around the end of last week, I noticed that she was perching on the lowest rung of the roosts instead of toward the middle rungs like she usually did. I thought nothing of it. Not long after that, I hung a shower curtain in the coop door to lower the amount of wind that blows in in the winter (the only door on the coop is a human-sized door). There are small holes cut at the top of the shower curtain and a popdoor-sized hole cut at the bottom of the curtain for the girls. When Blizz first tried to get out the door past the shower curtain, she acted as if she couldn't tell it was there. She kept running into it until she found the hole. Yesterday, I noticed she was acting dizzy. She would stand still, but her head would move slowly in a single direction. She would be looking around with her head moving like this, as if trying and failing at focusing on something. She was still free-ranging normally otherwise. Today, she acted as if she couldn't hop down from things. I heard her fall off the perches at about 3 am last night and found her on the coop floor this morning. When the door opened and she could see, she stepped up onto the edge of the food dish (maybe 4 inches off the ground) and kept turning around like she didn't realize that she could hop down from it. I moved her to the floor and then she followed me to the door of the coop and stood there like she wasn't able to hop the half foot to the step. She would not leave the coop today. I made sure that there was water within her reach (I have a heated bucket in the coop during the day). I brought her over to the bucket and splashed the water a bit to show her it was there. Blizz was very interested in the water, but wouldn't drink. She was not on the perch when I got home from school this evening (it was roost-time by the time I got home). I found her underneath the lowest rung of the roosts. It is possible that Frou-frou knocked her down after she roosted on her own (because Frou-frou doesn't realize she's bigger than most of the other girls and she tries to crawl under them on the roosts). She perched fine when I put her up on one of the roosts (these are 2x4s with the flat side up). Her crop is emptying normally. She does not feel like she is internally laying or anything. Her egg production has slowed in the past year, but I think she's just reaching the end of her egg-laying days. I don't think she has gone blind, as her eyes are clear and she followed my hand a few days ago. She didn't seem to have much of an appetite as of this evening, but it felt like her crop had a little water in it. She did have just a little bit of poo in her vent feathers, but I haven't seen signs of diarrhea (however, she could still have some going on). The flock free-ranges almost every day, so it is possible that she got into something, but I haven't come across anything myself. There are no other birds in the flock showing symptoms. The coop is not insulated and I use sand across the entire floor with a little Sweet PDZ mixed in. We've had some pretty cold weather lately, probably around 35 degrees F during the day. Most of the other birds are molting, but I haven't seen Blizz start her molt yet. I have not administered anything yet. I planned on adding vitamin/electrolyte mix to their water tomorrow. Is that okay to do with a heated bucket? Also, should I try to get Blizz to eat some scrambled eggs or something as a boost? I didn't want to remove her from the flock in case that would stress her, but I do have the means to bring her inside the house. If she is in the warmth of the house for long enough to get used to it, will she need to stay in all winter? Would she need a friend? Any other ideas? Please let me know if I need to give any more information! This was all I could think of for now!