I agree with Cherie6446, the burping may be caused by eating too fast. Another side effect is bloat and that can be dangerous. There are bowls you can buy that slow down how fast they can eat.
Pet Parade Large Slow'Em Down Pet Bowl | CSN Stores
You can feed you dogs different foods. I found that by making the dogs sit before you place the bowl down, and not allowing them to eat, until you give the release command, teaches them that they are not allowed to eat or disturb anyone else’s food.