The littlest dog’s sometimes can be the most unbalanced. My last neighbor had some dachshund’s and one of them bit me, a couple of their friends and their little kid! My new neighbor has some small dogs and their always yapping like they are big shots. I have also seen some small dogs at the dog park that play on the big dog side and push some big dogs around.
My dad used to raise Chihuahuas, back before I was born, in the first Chihuahua Craze of the late 1950s/early 1960s. He described to me an incident in which one Chihuahua chased two German Shepherd dogs down the street. (This occurred on an AFB, so it was likely that those two dogs were trained police dogs.) Then there was the time I was leaving the vet’s with my Chihuahua, and while I was writing the check, he decides to pick a fight with a waiting patient...A Rottweiler. My Chi growled in what he clearly thought was a deep and menacing manner in his throat, and the Rottweiler-a nearly full grown puppy, and a sweet, friendly dog-thought he was being invited to play a dog game. The Rottweiler’s owner dropped the pup’s leash, and the Rottweiler approached my Chi, smiling and wagging his tail. Then Mr Macho backed up rapidly till he was safely behind my legs-and then he starts growling and barking more loudly. I picked him up and tried to use the other patrons in the waiting area as a learning session for the chi-namely, on the difference between “laughing AT” and “laughing WITH”, but I don’t think the lesson took.