Thank you for the update. I'm glad to hear that the lump has gone down. I hope she starts doing much better.
Let us know how she is in a couple of days:)
It could be a ruptured air sac, sometimes those can repair on their own-could have been why she was having breathing problems. Since she seems to be doing better, then I would just watch the spot for the next 24hrs to see if it goes down.
The lump-does it feel like it has air in it or is it hard?
In the video, there is a "line" is that the vein?
Have you noticed if any of the chicks have been pulling out her feathers?
Has her breathing continued to improve?
She is breathing quite heavily, like she is too hot, I would try decreasing the amount of heat she is getting to see if that helps. You mention that she seems better when hydrated-see that she is drinking well. She will be o.k. for a few hours without food. Once she is hydrated, then offer...
Can you post some photos or a video of her? upload videos to youtube, then provide us a link. (photos of her, the brooder, her poop, etc.).
How old is she?
It does sound like she is overheating, how feathered in is she?
I would definately check her crop to see if it's emptying overnight - it...