Vienna sausages fall into two categories: The European version and the version from North America, brought over by European immigrants in the early 1900's.
North American takes are mini-sized and stuffed in a can, made with leftover meat like chicken, beef, and pork. The European version is more of an artisan-style take on sausage.
European Vienna sausages look like thin hot dogs and are made mostly with cured pork encased in sheep intestine. They can also be made with ground turkey, chicken, and beef.
Meat, preservatives, and spices like onion and garlic are the foundation of canned Vienna sausages. Ingredient labels typically list beef, pork, and mechanically separated chicken.
Natural flavors, sugar, salt, and the preservative sodium nitrite are also usually included in canned Vienna sausages. The whole thing is canned in chicken broth.