I have noticed that many people supplement their boxies' diets with dog food. From a nutritional standpoint, why dog food as opposed to cat food, etc.?

"Nutrition" is probably my weakest point of knowledge, so as a general rule I tend to stick to store-bought boxie foods that I then supplement with fresh fruits & veggies.

I try to feed them a variety of things, but I want to know they are being fed properly.