What is it about the little dogs? They can be really nasty.
There's a pair of Shelties a few doors down from me, and they're the terror of my neighborhood. I think my boy has a few problems, but he's an angel compared to these anti-social demon dogs.
Did your little Aussie have any training? Herding breeds are not for everyone, and they need to be trained, otherwise they can get very frustrated without a job or lots of activity. This could translate into aggression. Does the dog get lots of exercise outdoors off leash, or is he just a house dog?
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