I have had this before with a litter- not nice.
Everyday I would go down and se one had got worse and worse and they were getting worse everyday. I would never re home them, until you are certain that they are 100% fine. If its just the breathing then it could be some infection but if one looks squashed then it suggests they are pretty deformed.
I culled the litter as it was clear that they were fecked and in pain. Run your finger down there spines, are they bent?
Do what you think is right but I wouldnt rehome as you dont know whats gonna happen to them.
Good luck,
HJ