Dog vomiting after eating

Took him to the vet. Temperature was good. Eyes were clear and bright. Gums looked good. The vet took blood to run tests on to see if he could see anything out of normal. He is supposed to call back if he finds anything. If nothing comes back in the blood work, he wants to run x-rays. He said it could be a number of things but he is concerned about him as well. I have cut him way back on feed and he seems to be doing a little better. I am going to try to just slowly increase it back to his normal diet and see what happens. Of coarse he will be going back to the vet to get looked at either way. He is my main strike dog that I raised from a pup and there is no way I would let anything happen to him.