mouse getting fat fast

Question
QUESTION: I just got some new mice Snickers and Pumpkin. Snickers is a boy Pumpkin a girl. They are not from the same litter and she looking a bit chubbier in the stomach area!!! They have been together for 8 days now. Do you think they have already mated? If you do, how long do you think until she has them?

ANSWER: Dear Jaxi,

Snickers and Pumpkin may have mated on the first day, which would mean the babies could be due in 13 days!  Mice are pregnant for 21 days.

squeaks n giggles,

Natasha

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

QUESTION:
Sorry,, they have been together for only 5 days and every day she looks bigger. Could it be she likes the food or whatever ?

Answer
Dear Jaxi,

A pregnant mouse would not show on the 5th day, so that can't be it.

It is not normal for a mouse to gain weight that fast (unless all she is eating is butter or cheese).  Pumpkin should go to a vet.  There are a number of things which could be wrong, some of which may be treatable.  I hope she is OK.

squeaks,

Natasha