He's gorgeous! It's always hard to guess breed mixes based on appearance alone, as physical appearance is determined by such a small percentage of DNA. It's always fun to guess, though! I've worked in various animal industries for years, and we always start a poll when someone submits their dog for DNA testing. My guess for the predominant breeds is either Belgian Malinois or German Shepherd, then Staffordshire terrier.
Congratulations on finding such a fantastic dog, and I hope you update us once his results are in!
Won't somebody think of the rapist's feelings?