sick mouse

Question
We have had pet mice for one year now.  One of the mice, a female, started acting strange about 8 months after we got her.  She would sit all hunched up and her breathing was very shallow and rapid.  After a few minutes of this, she would behave normally for awhile, eat, walk around, etc.  Then she would again be very lethargic and seem not to be able to breathe properly.  After about two weeks of this, she died.  Now we have bought another mouse, from the same pet store, I might add.  We have had her now for about 2 months, and up til now she has been doing great, growing, eating and behaving normally.  Now this morning I discovered her just squatting in the food dish, not eating, her eyes shut and she felt very cold.  She seems to have very rapid and shallow breathing, just like the deceased mouse.  Do you think the spray I use against mites could be the cause?  I spray the bottom of the cage once a week when I change the bedding (wood shavings), and I spray the mice themselves once every two weeks.  Our other mouse seems to be healthy (we got her from a different pet store), aside from having squinty eyes.  I (and especially my son, whose mice they are, would be very grateful for your answer.

Answer
remove the wood shavings and stop using the disinfectant.  Replace wood shavings with wooden cat litter (pellets) as there is no dust.  I still suggest you take her to the vet for antibiotics or other medication.  I have experienced this in my mice I breed and changing to wooden pelleted cat litter seemed to work.