While corn is not, in and of itself, "bad" or dangerous for your dog (after all, it's often used in dog food--and cat food, for that matter), it also is not what you could call "good" for them, either. They can't digest it properly, so what little nutrition it does have isn't absorbed. It basically just makes your dog poop more. So, why do pet food companies use it, you ask? THAT is no mystery: it's a really cheap filler, which means--bigger profits for the companies. I personally look for pet food with little or no corn--dogs and cats are carnivores. Oh--and when you're sharing your popcorn with your dog, be sure it doesn't have any onion or garlic flavorings on it, as they ARE toxic to dogs--it can cause a form of anemia which can kill them (cats, too).