The ones you refer to are made of finely ground 'leftovers' including,skin, head, ears,gristle, brain tissue, and internal organs. They add artificial red food colour to make the mixture look like meat, it would be grey otherwise!
As all those parts come from a pig they can still be called 'Pork'.
Our local butcher sells a wide range of his own home made sausages, they are from 75 to 86 % lean pork shoulder cut into small pieces rather than minced.
They have won many awards.