I have two siberian husky australian sheperd mixes, they are roughly seven or eight years old. Their names are Fire and Ice. They were littermates, so they get along fine, but Ice is my dominant one, and Fire is the submisive. They seem to be dog aggresive, I dont know for sure if it is fear based, though I doubt it is. And I also dont know if they were socialized well when they were little since we got them when they were about two years old. But when ever I take Ice for a walk or even try to let her meet my new dog she goes pretty much crazy. When we are walking and we see a dog she begins to whine and lunge, sometimes she tries to get out of her harness/collar. When she is in her dog run and I bring my little Jack Rat out she starts barking, jumping and pulling at the chain link fence of the dog run they stay in. Fire is different when shes by herself, when I go by a dog she doesnt really care as long as the dog doesnt come to close, if it does then she snaps at it and bares her teeth, all with out warning, which means I have a little trouble correcting her. She is fine in her pen just paces or watches her sister go crazy. And yes I do walk my dogs frequently often for a few miles, so I dont think its pent up energy. I also train dogs and have trained them well except for this, i've tried many things to help them but I need some more help.