I really don't know what to tell you about inducing vomitting. I have never had to do it either. I know my dog used to make himself sick by eating mice. I know strange dog. He used to actually mouse hunt in the garden and it always made him sick and vomit. He used to vomit several times and he also used to vomit foam. The first time we seen these we called the vet as we were scared as well but the vet said it was nothing to worry about. He say simply put "the dog had expelled the item they was making him vomit but the feeling was still there so there was nothing left to vomit." Kinda like us when we get sick and vomit but there is nothing in our stomachs. All we get is the icky yellow stuff. Same concept atleast that is what our vet told us. But if you are really worried call your vet and get their opinion. It's always your best bet.