OK, this goes against my short-dog-dislikings, but! also consider a Yorkie: incredibly intelligent breed. Very trainable obviously, and also there was this one sad article which I read last year that's still in my memory: a Yorkie laid on top of a toddler during a house fire, perishing in the process, before the fire fighters got there, having saved the kid. How's that in the whole "dog vs cat" debate thing. Anyway, I suppose that was a crude, terrible example, but yeah, apparently dogs are capable of that sort of thing.