Yesterday me and my German Shepherd spent about 15 minutes chasing a mouse around the barn. Two things happened that I didn’t expect; first, she caught it. Then, when I tried to get it from her she casually crushed it up and swallowed it whole. No more recreational mouse chasing.
Dogs seem to have an instinct for rodent catching; some better than others! My Sheltie is useless for catching things. He's had squirrels and even a ground hog right in his mouth and then spat them right out. Mice he's afraid of, believe it or not!