Mixed-breed dogs

alt=An American Mongrel Dog|thumb|A bi-color mongrel. DNA sequencing shows a heritage of Boxer, American Pit Bull, and [[Great Dane, amongst others.]] A mongrel, mutt, or mixed-breed dog is any dog which does not belong to one officially recognized breed. While such terms may refer to all dogs of mixed breeds, the terms "dog crossbreed" and "designer dog" specifically refer to mixed-breed dogs which are intentionally bred.

A cur was a dog breed used by cattle drovers in England. In the United States, a short-haired dog used in hunting and herding is called "cur-tailed", or "cur" for short.