inbreeding

Question
Okay, i love my mice very very much, i just got them this week, i bought the male because i couldn't wait for my boyfriend to get me one, but then he got me a female from the same pet shop. i chose the pet shop because they usually sell there mice as food, and i didn't want that to happen. my problem is i got a male, and my boyfriend got me a female. the female is much bigger ( the males a baby) and I'm afraid she might be his mother. they get along great, but i don't want them to mate and inbreed. i wouldn't know what to do with the babies. and i don't want them to be diseased because of my carelessness. can you get a male mouse fixed? what the best thing to do? will a mother and son mate together?

Answer
Hi Kacie,

Unless that particular shop breeds their own mice, I highly doubt they are mother and son.  Most pet shops that do not do their own breeding take in mice from other breeders or order them from massive companies, both of which would reduce the chance of your two specific mice being that closely related.  If the shop does breed their own mice, you can ask the shop owner for records to find out about your pair.

Inbreeding does not cause disease, and many responsible breeders use inbreeding on occasion anyways to lock in desirable traits.  The problem would arise if they had been inbred a high number of generations before you got them AND carried disease-causing genes already.  Your biggest problem, however, would be not knowing what to do with the babies, as this would cause a problem even in non-related mice.  Since you know that you don't want pups, you should house them in separate cages for the time being.  Males can get females pregnant starting at around 8 weeks old, and will mate with any female whether related or not.  Some vets will neuter mice, but many won't as the procedure is very risky for such small animals.  You should call your local vets and see if any of them are able.  I'm not sure about the behavior of a male mouse after neutering, but I know that before neutering they prefer to be housed alone anyways and do not get along well with other mice for long periods of time.

If none of the options work out for you, you could try and find a good home for one or the other mouse.  Females do well in groups, so if you keep her, it would be a good idea to get her some friends.  If you keep the male, however, he should be the only mouse in his cage.

Best of luck in whichever you decide to do,
-Tam