Some dogs will vomit with every meal because they eat too fast. There is a little trick that we have used with a lot of success. We add several raw baby carrots to their meal. They will either stop long enough to move the carrot out of the way or they will stop to chew the carrot up. Either way, it slows them down and keeps the food down.
I would also add some tagamet or pepcid to his routine, just in case reflux is the culprit.
Let me know if you want to discuss this more. I would be happy to answer further questions.