Yep I'm pretty sure he'd be the result of a bullarab(breed on pittbull,cattle,greyhound lines) breed back to a high % sighthound dog. I could be wrong but I have seen many like him in pigdog breeders breeding programes.
Breed like this for speed,hunting ability & train ability with great stamia & strengh compared to their size.
Very trainable good dogs given the right start. Will try & find some pics for you.