The worst parts of the animal that can't be used in other meat products, covered in raw carbs, and of course, deep fried in oil. America.
(edit) I looked up some pictures, why is the bread so fucking thick? Is it supposed to absorb the oil or is that just a happy coincidence? Absolutely disgusting.
Think more like a slurry of connective tissue, bits of fat, and scraps of meat pressure washed off the bone and swept into a drain. The legally allowable quantities of cleaning chemicals and feces are also pretty concerning...
I'm happy to eat sausage, even blood sausage, despite knowing what it is and how it's made... but hotdogs are gross in a unique and unnatural way