Baby mouse:Hand-feeding complication?

Question
My sister and I found baby mice Saturday night (it's now late Tuesday), and fearing that the cat would get them before the mother could return I decided to take care of them. One, in particular, has been very energetic and seemed healthy until earlier today. It was eating fine and walking the best it could, being an estimated 5 days old. I have been keeping it in a small critter carrier on a folded T-shirt, wrapped loosely in a tissue to mimic a nest and under a desk lamp for heat. I have been feeding regularly and helping it "go potty" the way I read to on so many sites. All of a sudden the poor guy is a little bit weaker, is not eating as much and seems to be gasping for air ( I don't hear breaths, but it holds its mouth wide open and there are no tongue movements to indicate it's trying to nurse). Could this be dehydration? Or am I misreading its movements? I read that the formula would keep it hydrated fine. One more question; Do mice get gas? The way it's moving sometimes makes me feel like there may be some pain...I hope not :( I've become kinda attached in these few days and am doing my best to keep it comfortable. I'm also considering calling a petshop to see if they have a mother mouse that could possibly foster? Seems the best idea, it's just hard to give up my efforts. Any response is appreciated :)

Answer
Dear Stacy,

if the mouse is walking it's older than 5 days. You'll know their age when they open their eyes at 14 days.

The problem with hand raising baby mice is that you are not a mother mouse. Its a difficult thing for a human to do, and it isn't always successful even with the best of care.  It is best to give them to a mother mouse if you can find one. Gasping would not mean dehydration.  One thing it could mean is pneumonia. If the mouse managed to breathe in some of the formula during a feeding, it could have fluid in its lungs, which makes it hard to breathe.  Sadly enough it probably won't survive.  I don't know if mice get gas, but it's certainly possible that some part of him is not working properly, again, due to not getting the best of mother-mouse care.  It's also possible that he just has a congenital defect.  Not all mice survive babyhood. I'm sorry.

On the bright side, the others will make lovely pets.  Do separate the boys from the girls two weeks after they open their eyes. You don't want loads of little pets.

I wish you the very best of luck.

squeaks,

Natasha