Hi there, I don't think it is normal for someone to crop and dock a dog unless they had a plan for it.  So since this dog is cropped and docked it could be that it was purpose bred.  The Dobey influence is heave there but so is something else.  I am going to take a guess that it could have some chocolate lab in the blood or you may actually have a Canis Panther on your hands.  Check out more photos.