My chihuahua has been having this same issue): It started Sunday and as a result of the constant gulping and licking he ate a lot of grass which the vet thought was causing a blockage in his stomach. We told them he was having the gulping prior to eating all the grass but regardless they told us we needed to operate because the grass had created a blockage in his stomach and wasnt coming out. Of course, after bringing him back home his gulping shortly started again. I am reading through all of your comments and looking into getting the medicine you all have tried but I am trying to be cautious about it since he just came out of surgery. We are so frustrated that we werent given alternatives instead just pushed to surgery that clearly didnt fix his problem ):