Denise, ten ton of stuff out there that are harmful to dogs if eaten. With most of the 'edible' stuff on that list, its all about moderation. My old mums little terrier thingy gets chocolate daily, usually the last bit of a kitkat or something. Got it all her life and she's about 13. Had a dog that loved grapes too.. well, he loved catching 'em an ate 'em too, he lived to a ripe old age but sommat far more deadly to dogs seen him off... a car! And garlic is very good for dogs.
The one i'm always wary of, especially when we've had a bbq or at a show, is corn on the cob husks, usually dren