On Friday we noticed that Rem (aka Mom Mouse) was looking a bit thin and was breathing and walking a bit more laboredly than usual, so we took her to the vet on Saturday morning. The vet diagnosed an unknown respiratory infection (no surprise there), and after cautioning us that recovery rates aren't great for this sort of thing (again, no surprise there), he gave her an injection of an antibiotic (Baytril) and gave us some of the antibiotic to feed her twice daily for the next two weeks. Of course, the infection could very well be viral, but it's the best he could do.
The antibiotic was supposed to be flavored so that Rem would eat it, but she was more interested in trying to climb on the dispensing syringe than lick the end of it, so we went to plan B and are now mixing the antibiotic in with some melted ice cream (Ben & Jerry's ... nothing but the best for our sick mouse). She is now happily licking up the antibiotic ice cream.
Rem's looking a bit better today than she was yesterday, so hopefully the antibiotics and prolific treats are doing the trick, but we'll just have to wait and see.