You need to keep your best friend safe from dangers around your home, but some of the most toxic things are sitting on your dinner plate. Source: Christchurch City Council When you think poison, you probably don't think of dark chocolate, sugarless gum, macadamia nuts or cigarette butts. They're not the kind of thing you lock up in a cupboard to make sure your dog doesn’t have access to them. You should, because all of the above can be toxic to a dog. Dark chocolate contains caffeine and theobromice in toxic levels; white chocolate has almost none and milk chocolate