dying mouse

Question
as I'm writing this, I have one of my male mice next to me, wrapped in a tissue. He isn't moving anything but his head, and he's breathing through his mouth.
I'm quite sure he's not going to survive until I get an answer, so I'm just trying to keep him as comfy as possible :(

I don't know what he's dying of, though, and I'd really like to know. He had food and water, and he was in his own cage because he started fighting with his other littermates when he was younger( i think he's about 2years now). I can't see any tumors, injuries or anything.His eyes are slightly open, and when he breathes, he looks like he's gasping...

Its really sad to watch him, because he was one of those accidental babies that happen when pet shops sell you male mice that are labelled as female :\( I had 3 females in the cage )He was born slightly defected (mising 2 toes on his left foot) but I'm not sure if he could have an internal defect or something... I have no idea :(

please help

Answer
Dear Bec,

I'm so sorry about your little mouse.  There's no way I can tell what went wrong.  If it was a slow thing, like he has been getting weaker and is hunched over, then it's just old age.  2 years old is very good for a mouse.  If it was more sudden, then he may have gotten an illness which was just too much for his aging immune system.  Other possibilities are if he was dropped, exposed to harsh temperatures or chemicals, or ate something poisonous.  

When he dies please don't be alarmed if he has a kind of a fit.  Mice often convulse at death, and it can be very violent and thus very alarming.  Just hold him in your hand if he likes it, and he will go happy.  

It sounds like he was a special mouse.  I always like the ones who are a little bit different (missing toes).  

If you still have other mice, make sure you wash your hands thoroughly after handling him so the other mice don't get sick, and watch them carefully for any signs of illness.  If you don't, it's time to get new mice : ).  If they aren't too young you should be able to see if they are boys or girls.  I always recommend 2 or 3 girls.

Again, sorry about the little mouse.

squeaks,

Natasha