I don’t know of specific benefits, but regular dog food has ingredients that puppy food does not–especially for that adult dog. 🙂 Our pit bull is about the same age as yours, and is eating adult food, a maintenance blend. We wondered if a large breed food would be appropriate, or something else. Just weigh your options, think about the ingredients–a meat, a grain, some fats are good, perhaps vitamins/minerals. It seems to me the more natural the better; I’ve heard about a lot of sensitive pittie stomachs on this site. 😛 Oh, goodness–our pit bulls are so sensitive, even their stomachs. 🙂
I hope all goes well with the food switch. Sometimes they’ll be real sensitive, but if your dog is anything like mine, he doesn’t care what he gets a hold of, as long as it tastes good (and of course, is good for him, lol; at least we as the owners know that; he doesn’t). 😛 oh, dogs…I love ’em!