I'd withhold food and water for a few hours and just watch him. If he seems in pain or uncomfortable in any way, by all means, take him in. If he seems okay, try giving him a couple of ice cubes to chew on in a couple of hours. If that stays down, water this afternoon and if he still is okay, try the boiled hamburger (with the fat poured off) and some rice tonight. A very small amount....mayb e 1/4 of what he usually gets. Tomorrow morning, increase the am't of the rice and meat to maybe half of the normal am't with all the water he wants and then by tomorrow night, if all is well, try his normal diet. If at any time he can't keep the food and water down, take him in.