The Sanguinius Werewolf is the result of genetics, rather than being bitten. Since, the gene for becoming a werewolf is recessive, the only way to become a Sanguinius or Blood Werewolf, is if both parents were werewolves. The first recorded Sanguinius Werewolf was reported in 1902, the first year that the parents were allowed to keep their children. The child's name was Serpens Orror, and he only lived to be sixteen. The parents couldn't keep up with the potion in addition to their transformations, and the Ministry put Serpens to death. Shortly after, his parents, Zuppa and Gelica died of grief. Now the Head of the Werewolf Liaisons office is trying to get a law passed that will provide a potion-maker for each werewolf family. Reportedly, there were no Sanguinius Werewolves before 1902, but parents were not entirely honest with the Ministry, and unconfirmed sightings of Blood Werewolves occured as far back as when the first Prime Werewolf was bitten by the Significus Werewolf, or first. The Significus Werewolf could be considered a Blood Werewolf, except it had no werewolf parents. That werewolf was the result of an unknown mutation.
The Sanguinius Werewolf has a shorter lifespan than that of a Prime Werewolf, or one who was bitten. While the Prime Werewolf lives to be around 70, the Sanguinius Werewolf only lives to about 50. This is the result of much harsher transformations, as there is less human blood. The transformations are more violent, and can shift quickly between states of high activity, low activity, and being aware of who they are. This makes the transformations hard on body and mind. Also, the transformations last from three days before the full moon starts to three days after the full moon has waned, which is a longer span of time than that the Prime Werewolf must endure. If a Sanguinius Werewolf is not given the counter potion starting from age ten, then at age 35, the transformations will become yet more violent. At age 45, the transformation will become permanent.
The bite of the Blood Werewolf will still produce a Prime Werewolf, but the Ministry typically puts Blood Werewolves to death because their transformations last longer, and that gives them more time in which they are dangerous. It is against the law for werewolves to breed, but if they do, the Ministry has declared that the parents may keep their child, if and only if, they feed them the counter potion consistently from age ten. The counter potion affects the mental part of transformations, so the Sanguinius Wolf will keep their mind, but physically the transformations are still torture, and they will still only live to about 50, although some have lived to be 55. To brew the counter potion, Sanguinius Deterrus, you must grab hairs from the tail of a Unicorn at the new moon. Also, lacewing flies, salamander blood, and moonstone dust are required for the potion. The flies, blood, and dust must simmer in a cauldron for six days before the new moon, and then you add the Unicorn hair whole. Stir the mixture counterclockwise six times every day at noon until three days before the full moon, when it may be fed to the Sanguinius Werewolf.
This type of werewolf, while rare, is particularly dangerous. The only way to recognize it from a Prime Werewolf, is too look at the skin. Blood Wolves are a bloodier red during their transformation. While Sanguinius Werewolves are dangerous longer, their transformations are so violent that they rarely attack. They are often incapacitated by pain, but it is still advisable for people to be wary of them near the full moon.