Not that I’m an expert in cuss words or anything, but as a person who is bilingual in Korean and English, here is my understanding.
irmar is right that when you call someone 개새끼 (gae saekki), there is no prostitute connotation. Gae = dog; Saekki = off spring/child/pup. It could be short for Son of Dog or for Dog-like-being (개같은 자식//새끼 Gae Kateun Jjashik/Saekki). So in the second sense, parents are not involved and you are only insulting the offending guy.
It’s not that Koreans hate dogs more than other animals, but when you are calling someone a dog, it’s basically saying you are worse than human. As for eating dogs, a lot of Koreans actually do not eat dogs. It’s mostly the older generation (mostly men, but some women as well) who enjoy eating dog stew. Some Koreans believe that dog meat is great for men’s stamina and others believe that eating hot dog stew helps you overcome the extreme heat in the summer, etc. Koreans believe in 이열치열 (以熱治熱) - You overcome heat by eating hot food, and overcome cold by cold. I honestly think that Korean started eating dog meat long time ago when they were so poor that any meat would help them survive. And even though who do enjoy dog stew, it’s not like they just kill their own puppies or pet and serve them for dinner! That would cause an outrage. Koreans love their pets, too. For those who want to eat dog, they have to go to a specialized dog stew restaurant (which isn’t a lot as it’s not that popular) and eat the food there. I personally never had it, nor do I have any desire to try it ever! Well, if I’m starving to death… maybe… hmm. Let’s not go there. I digress…
Let me get back to the main topic.
The thing about keep the curse words the way it is while translating is that there often isn’t a one-to-one relationship between curse words in Korean and curse words in English. For example, saekki means “off spring.” In Korean, it could be used like bitch, son of bitch, asshole, jerk, punk, and yet, depending on the context, it could simply mean my lovely child, or just a playful term between friends. Another example is 년 (nyun) or 미친년 michinnyun (crazy girl/bitch). It could mean something like bitch, crazy biatch, or it could just be a sarcastic or playful or scolding term used by her own mom and obviously her mom isn’t calling her a bitch! So I really hate it when people just blankly sub Nyun as Bitch and Jjashik/Saekki as SOB. I honestly don’t think Koreans in general doesn’t curse as much as Americans, unless if you are part of a gangster or something. So that’s why when I translate Korean cuss words, it always turns out a bit milder in English. It’s not because I’m trying to sanitize or censor cuss words but I try to translate based on the connotation of what is being said in that context and it usually turns out to be milder terms in English.
Well, I hope I didn’t confuse you more.