It depends how injured it is. My mouse had part of its tail cut, the part simply died off slowly, and a shorter stubby tail developed. The problem will be probably fixed over time but take the mouse to vet asap just incase.
Sneezing and/or squeaking aren't characteristics of pregnant mice, this means it is possible that the mouse is sick and you may want to consider taking it to the vet. If the mouse has given birth then squeaking is very, very common from the baby mice as they 'talk' to their mother (mouse) so they can get fed and looked after.
Like all Sims 2, you haft to have a male and female have 100% on their relationship with the other, then you make them cuddle in the hot tub or bed then after that select "try for baby". Then after that you should hear a lullaby, if you don't your Sim isn't pregnant. Hoped it helped :)
Mice don't usually have a great deal of bladder control--they just let go when they need to. If you hold a mouse for any length of time, you will probably get peed on. However, it depends on the mouse, too--tame mice who trust you may wait awhile until they HAVE to go on you, and may even wait until you put them back in the cage. Mice who don't trust you will pee on you as soon as you pick them up. Some mice will also choose to pee in a certain corner of their cage, but many of them don't care. Like dogs and cats, male mice will use their pee to mark their territories.
i dont think you can but there is a way to make it stand by holding a tret above his head maybe if you hold it high enough he might jump for it