My Siberian Husky probably wouldn’t go after an intruder, but she is a big Husky (over 65 pounds) looks like a wolf with blue eyes, and has a bark/howl that is sort of scary which she does when a stranger comes to the door, where she can be seen through the glass. Our Chow never barked until the stranger had a hand on the doorbell, then he was suddenly THERE, displaying a mouth full of teeth and sounding like the end of the world. Chows still have a pretty bad rep, right up there with Staffordshires, Dobies, Rotts, etc. When I was a kid, that list didn’t include Staffordshires, but did include German Shepherds.
I personally think the worst biter in the dog world is a Chihuahua-I wouldn’t tangle with ANY barking dog, no matter the size.
Nor would I. I think that’s the problem - too much human error and total lack of understanding of basic canine behavior. That - and negligence, carelessness, cruelty, etc... along with a healthy dose of stupidity. Agree that smaller dogs can be very very aggressive - and Chihuahuas do have a rep. for being a bit aggressive.