Aggressive Miniature Dachshund
I know by the type of dog, it seems hard to see it as aggressive, although he very much is.
We first got our dog from the pound, where at the pound he was scared, but still pretty sweet. He had some things that needed to be done at the vet with shots and etc. And even after he was still a good dog.
After about two to three months he began to become aggressive. He would "hoard" toys, food, etc. from our other dogs and over time would not even let us within the home touch any of "his" things.
It has now been almost three years and it has grown to an extreme aggression. He will growl and bare his teeth whenever someone is near him or tries to touch him, he chases people out the door as the leave, and almost altogether prevents anyone from entering the house. When someone in the house opens their door he will run down the hallway and try to bite them. Even walking down the hallway will trigger him, and on occasion he has bitten some of us on the leg. If we try to discipline him, he will turn around and bite us. I have tried many things encouraged by trainers in my area, but nothing has seemed to work. It is really putting a strain on the desire to keep him. I would do anything to be able to keep him in my home.