I've isolated him from the other chickens and keeping him in the laundry to keep him warm.
He sounds croaky when he breathes as well
I've posted in that thread but no replies as of yet
He is the first rooster we have had and hasn't been picked on by any other chickens. He has been happy and walking around for the first few days we had him and then started staying in one spot, tucking his head into the feathers and closing his eyes most of the time.
He has also stopped crowing...