why is my mouse bleeding

Question
i have both a male and a female mouse in the same cage. yes i know they will mate which im ok with as i plan on caring for the babies as well as parents. anyway the other day when i put them together he had sex with her right away and for a good long time and here 2 days later i noticed my female is bleeding a little bit from her private and not sure why? also the box i have in their for them to play/sleep in is all covered with blood as well. she seems to be ok and nothing else seems wrong but im a little worried and hope its nothing big. any help is appreciated

Answer
Thanks for taking the time to ask and use all experts.

There are several reasons a mouse may have this happen. Most commonly we would look as miscarriage. This can happen to any animal and you may only see blood because they will eat the baby if there is any problems even if it is born at a normal time, this is just their way of weeding out any weak babies. The second thing to consider is urinary tract infections or UTI. Antibiotics from a vet is the only way to take care of a UTI. The signs for this are:
-frequent urination
-licking of the private area
-crying or squeaking when urinating
-fever or abnormally hot to the touch
-blood
Another possibility is tumor. This is something that your vet will need to do blood work to determine. You need to watch for hard areas or lumps on your mouse.

I would first clean the cage and your mouse very well and remove all evidence of blood. Then if you see the blood reappear then you need to seek a vet that is qualified with rodents. For pain there is some options of you feel she may be in any. I am including a chart that will give you over the counter medicine they can take, how often, and how much for a mouse.

http://rattitude.com/articles/information/pain-medication-guide-for-pet-rats-et-...

Also here are some link explaining more about the bleeding in mice that may help you further.

http://petcare.suite101.com/article.cfm/why_is_my_pet_peeing_blood

http://www.rmca.org/Articles/qna5_97.htm

I hope this helps and feel free to ask as many question as you may need if you need further assistance. Thanks and good luck!