My dog doesn't fit the description of what I've read about aggression. What's going on?
All of the articles I've read describe aggression as being fear-based. My dog's behavior doesn't match. My German Shepherd was adopted from the shelter and she showed early signs of reactivity on-leash. For a long time, we thought it was just leash reactivity. She played fine with dogs at the dog park, but was always a little "weird." She wouldn't let other dogs sniff her tail end, she would show dominant and subtly aggressive behaviors like puffing out her chest, mounting, and prancing around other dogs with tail and ears high. But she would also be pro-social, sniffing other dogs, engaging in play, accepting licking and pawing, etc. She started "stalking" other dogs- lowered body stance, staring like a border collie, and she would trot up to them and usually nothing would happen. But she then chased and attacked a very small dog- we thought it was just prey drive and no one was hurt. A few weeks later she attacked a larger dog out of the blue, no vocalization or anything. What gives?