Sanguinas Feralas
Also known as Feral Vampirism. Creatures afflicted with Sanguinas Feralas typically show all the same symptoms as normal Vampirism. However it also comes with the addition of being far more aggressive, losing much sense of reasoning, and crawling on all fours like a rabid animal. Creatures lose their eyes and nose, gaining blindsight instead.
It is still unknown why some Vampires turn feral, or when it first happened.