Can my dog die from eating a year old rat/mouse?

i was just wondering if it is possible for my dog (a pekingese) to die or become ill from eating a year old mouse or rat. i had pulled out the dresser and there was a large mouse in the mouse trap and while i was getting something to put it in the dog grabbed it and ate it under the bed. she has always been a strange dog. but theres nothing left except the trap. so i know she has ingested it.