Is it a puppy or adult? Really don't make too much difference, they are a lot like humans, they have their off days. One thing, if you think he had something wrong with him before he vomited, take him to the vet. If he was playing and happy before then, let it go outsde and eat some grass, or maybe it ate some when it was out earlier. Dogs will seek out the right grass to nibble on when they have a queasy stomach. Then they might vomit some, but not a whole lot, and they will be slow to move for hours but they usually spring back fast.If it continues, please take it to the vet.
