You can't hold your gas in forever; it's going to come out whether you're ready for it or not. Perhaps as a belch or perhaps as a fart, but regardless of form, it will escape. And sometimes in close proximity to (gasp) other people. Should you go ahead and hold it in, or is it healthier to always let it out and blame the dog? It's unlikely holding your flatus in will hurt you; although, it will likely cause you some physical pain, bloating, abdominal discomfort (including dyspepsia) and heartburn (pyrosis).