Wow, I think that is what my Niño looked like as a pup, minus the black patches! I see your sig, well, he looks like he might be part pit bull mix as that is the body shape of a puppy pit and terriers carry the gene for tick marks also, like my pup. I just can't belive how cute he is! Did you rescue him? He has cute little rose prick ears!
It looks like your family has something wrong with them, however! You might want to have that looked at. Black square face is obviously contagious, and spreads rapidly.