However, I have known dogs who ate chocolate with no bad effects to them at all! But best not to take the risk. Your dog
will throw up
, then a little while later, will feel perfectly OK, and probably hungry again. So you won't be doing him any harm.
Milk chocolate is less toxic than dark chocolate, and baking chocolate is the worst of all.
But don't induce vomiting if your dog has a history of epilepsy, heart disease, or is generally unwell.