A “cur” in dogfighting language, or to “cur out”, is any dog that is not a pit bull or is an inferior pit bull that quits a fight due to lack of gameness. Curs are frequently shot and killed for displaying such behavior, as being one is a gross embarrassment for its owner. Lucky the cur pit bull that is shot and killed. Others suffer horrible torture, such as being hosed down then electrocuted at the hands of people like Michael Vick.
“That black dog is a cur!” came the yell from the top of the stands. The noise in the barn dropped so quickly it was scary. It got so quiet the sound of the dogs feet scraping on the tarp could be heard, as every eye in the barn looked up to see who had labeled a dog that had never turned or hesitated in his life a “cur“. I thought big trouble lay only seconds away, as a slur like that cannot be ignored. The “Black Dog’s” handler looked up to the top row where the voice had come from and said, “I don’t appreciate you calling my dog a cur!” – Chatnjack, Game-Dog.com