Judycat's reply is a real eye opener. Almost scared the pants off me. But the point is simple, too much salt is bad for you. An adult's daily intake should be no more than six grams, that's about one small, level teaspoonful. The average hot dog sausage contains around five and three quarter grams. That's ok then, it's less than the recommended six grams. Not quite, the bread that the bun is made from contains two and three quarter grams, now you are almost fifty percent over the recommended limit.
Processed foods all contain dangerously high levels of salt, manufacturers know it, so to stop you worrying and keep on buying, they use salt's other name, sodium. It sounds Latin, kind of posh, must be good for you. My wife and I don't eat, any sausages, bacon, bread, cheese, burgers and whole lot more that would send you to sleep if I listed them. High levels of salt is up there with alcohol & tobacco, it's a killer.