yesterday he went crazy! He would not let anyone touch him, we were unable to put a collar on him. He was chasing his tail continously, he would not stop, He got real aggressive, would stalk and growl at us. Could not even get near him. He would just sit and stare at us with his eyes looking hollow or empty. Animal control came and took him with one hell of a fight. They said he needed to be put down. That he had a mental problem. All this happened so fast. Does anyone know what happened to our dog? Was it from his abused? Was it from birth? Is it hereditary?