Australian Shepherd (Arvada)

It's against my morals and ethics to give up on a pet that I have adopted but I have no choice. We raise chickens and he has now killed two of them. He had a tendency to chase them and several months ago he killed one. Tonight he purposely killed a chick then looked for praise. He also has a habit of chasing our two cats. Needs to be an only child. He is housebroken, loves to go on walks on a leash (will take off after rabbits and squirrels). Very loving dog to humans. We've tried everything to get him to quit his chasing but can't deal with him killing chickens or chicks.