Probably the most commonly eaten sausage in America, the frankfurter aka hot dog may be made from a variety of meats including beef, pork, veal, chicken or turkey. The precooked sausage tends to be high in fat and most contain liberal amount of controversial nitrates. There are all beef types that must by law contain only beef without fillers. Hot dogs tend to also be very high in sodium and fat.
There are some companies that are beginning to make a better quality product using grass-fed beef and fewer preservatives. Look for products from Longmeadow Ranch and Applegate Farms.