In case you don't know what raw blood pudding is, it's a dish that is literally made of fresh, uncooked blood from killing chickens, ducks or pigs, most commonly seen in Northern Vietnam.
You don't have to localize it. Add a TL note. Once upon a time it was like Japanese terms. Gotta start somewhere or else idiots will convert it into neesan/neechan just because 姊 can be read as ane(in Japanese) while the Vietnamese word being derived from the old Chinese pronounciation of 姊.