On average, about once every 2 weeks, my dog will act kind of mushy, not interested in his food or really anything for that matter. He'll usually throw up, at which point he seems to feel much better. The vomit is generally in a small amount (since he hasn't eaten), a yellowish liquid (bile?), very smelly. My vet says it's pretty normal and that one of his dogs is like that. He suggested giving him a piece of a pepsid ac or zantac tablet once a week or so, but you'd have to anestetize my dog to get him to take a pill. Other than this he seems to be in perfect health and such. He's a 4 1/2 year old shih tsu.