what spice or spices make hot sausage hot?

Answer 1

Typically, it's cayenne pepper and/or red pepper flakes, which I think is also cayenne. At least that's what I see in hot breakfast sausage, italian sausages and the cajun style sausages.

I'm sure there are specialy sausages that use other types of peppers, but a majority of the commercial stuff uses cayenne and red pepper flakes.

Also...
I forgot to mention, but hot paprika is use a lot too.
According to this website, the red pepper flakes are mostly Red Fresno Chiles
http://www.recipetips.com/glossary-term/t--36007/red-chile-pepper.asp

Answer 2

At this end of the earth a hot dog in called a Frankfurter. A sausage is a typical, Pork or beef sausage, (a banger). The typical German Bratwurst etc are called speciality sausages if not by there name. Speciality Sausages have a branch of Novelty sausages created by local butchers, eg, lamb and mint, venison and red wine, etc

Answer 3

Ground or flaked red peppers or ground or cracked black pepper or both in most hot sausages.

Bert