mouse has large stomach

Question
QUESTION: We bought a pair of mice from a pet store recently, and one of the mice has a increasingly large stomach.  The were both the same size when we first bought them, and now the one is about twice the size in the belly.  Her stomach also feels sort of like there are small lumps in it.  We looked around on the internet about sexing mice, and are not quite sure if the other mouse is female as they told us at the petshop.  We are worried she may die from this or, possibly give birth soon.  Please let us know what you think as soon as possible! Thanks!

ANSWER: Hi!

Easiest way to determine the sex of your mouse is by looking under their belly. If you see nipples, you're holding a girl, and if not, it's most likely a boy. For long-haired mice this may be a bit tricky though!

Apart from pregnancy the lumps and growing stomach may either mean a very aggressive tumour, or that the mouse simply carries the 'fat-gene'. Mice carry about 20 days, and if there are indeed babies I suggest you take a look at the very detailed information provided by the Finnish Show and Fancy Mice Club's site about breeding: http://hiiret.fi/eng/breeding/index.html

In case of sheer obesity, all you can do is watch her diet very carefully. Mice eat about one tablespoon of food (rodent chow, including grain, seeds, etc) per day and you shouldn't go over that! A safe running wheel (preferrably a plastic one without any holes, ~17cm wide. Traditional 'steel bar' style wheels are a hazard to the tail and legs, and wheels under 17cm are a hazard to the spine!) is a great form of exercise.

Hope this helps, good luck!

---------- FOLLOW-UP ----------

QUESTION: Two days ago we noticed squeaking coming for the cage and found 6 baby mice! We immediately took out what seems to be the male and brought him back to the store we got him from.  We had 2 females in there already, and they are both doing an excellent job at caring for the babies.  My question is, how soon should be be handling the babies to ensure they are tame? I've heard anywhere from 4 days to 2 weeks when reading up on the internet.  Also, what should the mother be eating? Anything extra?  She has a mix of the millets, sunflower seeds, peanuts, dried fruits and veggies, and more.  Thank you. very much for your help
ANSWER: Hi!

Congratulations on the unexpected additions to the family. :-) It varies from breeder to breeder how much and how soon they start handling the newborns. Some professional breeders choose not to handle the babies at all until after their 'flea-age' (3-5 weeks), personally I find the best pet-qualities coming from babies who've been handled all the way from 3 days old. Be very careful about it, as if the mother smells something 'odd' such as your scent on the babies, she may just abandon them! Wash your hands carefully and try to get as much of the scent from the bedding on your hands as you can before touching the babies or the nest. From 3 days to a week old the babies should be handled once a day for couple of minutes, increasing the time of handling as they grow older and starting to handle them twice a day from 1,5-2 weeks.

Mother's diet sounds good, you could also add some calcium in it in form of a boiled egg (no yolk), including bits of the shell. Once the babies start trying solid food, try to introduce many new flavours so that they won't be too picky when they grow up!

---------- FOLLOW-UP ----------

QUESTION: Its been about 2.5 weeks, and the babies are doing great!  My concern is that the mother has started ballooning up again, and even though we took the father out immediately after we discovered the babies, it looks like shes pregnant again.  If she has more babies, what do we do with the older ones?  Will they be ready to leave the mother by then?  I feel so bad for her having babies so soon like this, will she be okay?

Answer
The mother continues to store extra fat into her body during the nursing time, up to the point of it seeming like she's carrying again. But if she truly is pregnant already, well, it'll get quite crowded around there soon!

The first litter needs to be separated before the second litter is born, but not before their third week. Each boy into his own terrarium, girls should be kept as a group. The mother's body would certainly be under alot of stress from having a second litter so soon, but so long as her diet is alright she should be recovering quickly once she's got the second litter over and done with. Best regards to the little army!