Technically speaking, a hot dog is a type of sausage. So when asked if a hot dog is a sandwich, the answer is unequivocally no, it is a form of sausage originating from Frankfurt. It just so happens that when we want to eat or order a hot dog, the customary method of serving is inside bread roll, but 'hot dog' ISN'T the name of the whole bread+sausage+sauce, hot dog just refers to the meat, with the bread and sauce being how it is customarily served. There are places where you can order a 'hot dog' and all you get is a hot dog skewered on a stick (at festivals and stuff). so i think the question itself is flawed. if you ask someone whats the different between a bunnings snag and a hot dog, the difference is the meat, not the bread/how it is served. so hot dog definitely just refers to the meat, so the question of whether a hot dog is a sandwich is mute.