Kirsten Morrissette answered
A wild mouse is just as clean and good natured as its domestic counterpart. I cought one a few weeks ago and she is quite content in running on her wheel, eating the premo food I buy for my fancy rats and drinking the fresh well water. She is neat, clean and all around healthy. I avoided touching her for the first few days to check for illness/disease. Since I live out in the middle of no where, the animals out here have low risk for such things. Its suburban and city rodents you have to worry about because of pollution and disease. I recommend talking to your local health department for some statistics. Believe it or not, they keep track of reported incidents of sick rodents and can provide more answers. For now I say keep an eye on it. IF the mouse doesnt groom often, eat properly, stay hydrated, is extremely agrassive, shows signs of illness and doesnt work out (like on a wheel) get rid of it. Let me know if that helps.