fuzzy seems to have trouble breathing

Question
I recently saved an orphaned rat from the demise of a feed shed cleaning. Ive had him since monday ive been feeding him kmr (kitten formula for orphaned kittens) he was doing very well, but this morning he seems more lethargic and is sometimes gasping for air. he also makes like a clicking noise when he breathes, did i over feed him and cause teh formula to build in his lungs? Is that even possible? I think he may have some sort of fluid in his lungs but i really have no idea. He is approximately 11 days old, please help!

Answer
Most likely yes, he inhaled some formula while he was eating and aspirated - its very possible and happens even in adult rats while they're drinking sometimes. There really is nothing else you can do at this point other than keep him warm, keep him fed, and hope he's able to expel the fluid on his own.