Back in the day, “cur”was a term used to refer to mixed breeds or “mongrels,” and the word was used as an insult to a “ungentlemanly man” by suggesting that his ancestry was in question. That said, we’re not sure how the word made the leap to actual dog breeds, but there are many of them (not all recognized by the AKC), and some sources maintain that the Cur dog was the first true, distinct, American purebred dog.
There’s the Black Mouth Cur (recognized by U.K.C.in 1998), the Catahoula Leopard Dog (an AKC FSS breed), Stephen’s Cur (a scent hound originally bred by the Stephens family in southeastern Kentucky), the Leopard Cur (also called the American Leopard, American Leopard Cur and Leopard Cur), the Mountain Cur (also recognized by the United Kennel Club) and the Treeing Cur (a rugged, working dog originating in the Southern United States).
What all the Cur dogs seem to have in common is that they are multipurpose, tough working/hunting dogs with origins in the southern, southeastern United States. As far as we can tell, curs are developed solely for their hunting ability, and some might suggest that cur breeds are “types” rather than breeds. We’ll defer to the experts on that, but we found this statement to be fair: “Cur dogs are not the result of random cross breeding. You cannot “make” a Cur dog. Curs are specialized working dogs bred for ability by breeding the best to the best, based on individual performance and usually regardless of the actual breed. Several kennel clubs do however, register various Cur breeds based on their ancestry (bloodlines)” (this from the Dog Breed Info Center).
Image of a Stephen’s Cur from 2009 found on Wikicommons