We have a 7 month old mini Aussie that weighs around 15-20 lbs. At least once or twice a week she wakes up with what my kids call "bubble gut". Her tummy makes all kinds of noises, every once in awhile it's accompanied by her vomiting(usually just clear liquid or a very small amount of food). Other times she goes off her food briefly. No diarrhea(slightly softer stools but nothing loose), and she is as active as always. The times when she goes off her food she will beg at the door to be let out so she can eat grass. She has been to the vet, and they can't find anything wrong. I was told to give her 1/2 tsp of Maalox when she is refusing food. Today was the first time that's happened and within 10 min of getting the Maalox she wanted her food. She gets Purina Pro Plans puppy food, she was on Science Diet when we got her and the tummy aches were happening before the switch. I scheduled another vet visit for next week, need to get her started on heart worm preventative. Any ideas as to what could be causing this? She gets ZERO people food and the only treats she gets are Authority Peanut Butter and Banana treats. She also has a few rawhides she gets when someone can keep an eye on her.