Most good, hard hunting lines of cur dogs will have some hound bred in somewhere down the line. There...I said it!

. Heck, I know a lot of the East Texas black mouths did. Rumor even has it that the YBM could have originated as a black and tan / mastiff type cross. If someone thinks they have an antique line of curs with absolutely no hound in them, chances are they probably just haven't traced them back quite far enough.
I always suspected my dogs had hound bred in way down the line not only based on looks but also because of the "unconventional and houndy" way they hunt...not to mention they always bred true to color...either yellow or saddleback. It wasn't until just this past year that we confirmed the crossing in of trigg hound wwwaaayyy down the line.