He might be eating too fast or gulping air. Is it real soon after he eats? One of mine used to do that in the morning. I always figured that his tummy was so empty that he was inhaling his food. I started giving him just a handful of his food, then a bit later a little more, and then the rest of it. He stopped vomitting. I eventually started just pouring his kibble all over the bottom of his crate to make him eat slower. I also started saving a small amount of his evening meal to give right at bed time so he wasn’t going as long before getting more food in his stomach.
