Came across this info earlier, Sugar substitute Xylitol
Just a warning the  sugar substitute Xylitol is posionous to dogs one teaspoon will kill a GSD, this advice has come from UK vets. It is also in some processed foods/candies and sweets so please be aware, it acts like giving a dog insulin and there is no antidote. So if you have 2 teaspoons in you tea/coffee and the dog drinks it you have a serious problem on your hands. Please share as widely as possible.   http://vetmedicine.about.com/od/toxicology/qt/xylitol_tox.htm

good point to raise