Pregnant mouse and sick cagemate

Question
hi,
i bought a pair of female mice from the pet store yesterday, one i picked the other my mom did. Maverick (the one i picked) seems to be in good health but i think she maybe pregnant, her belly is dragging on the ground and she is wide at the hips. i gave her plenty of shredded tissue and she started nesting, my concern is that her litter mate Dex looks like she is sick. watery eyes, ruffled fur and lethargic. would it be better to remove Dex and put her in a separate cage so she wouldn't get the babies sick, or would that stress Maverick to much to care for her young?

Answer
Hi Hannah,

Unfortunately, it's a risky situation either way.  Although it might stress Maverick out and put the babies in danger, it's definitely better to separate Dex now because of the risk of transferring a disease.  Maverick may already be sick and not show it, but it isn't advisable to put her on any early treatments like general antibiotics because of her possible pregnancy.  Even once pups are born she can still deliver antibiotics through her milk, so no treatment is a good idea for her without a professional vet's recommendation.  If you know a vet you can ask, it would be worth a visit.

As far as Dex, who you know for sure is sick, an antibiotic may help and is definitely worth a shot.  Once a mouse starts looking sick it means the problem is already serious, so please do take her to a vet if you can.  If not, tetracycline is available inexpensively at most pet stores (check the fish section) and feed stores, and Natasha has some wonderful instructions on how to administer it here:  http://en.allexperts.com/q/Mice-3824/2010/2/Tetracycline-directions-sneezing-mou...  Remember to keep the bottle with the medication covered from light, and never use tetracycline that has expired, as it may decompose into harmful products.

Best of luck to both of them, and I hope that Maverick raises a happy, healthy litter!  Let me know if there is any other way I can help, or if there are any other questions you have.

-Tam