New here and am in need of answers,PLEASE! I have had GSD's all my life and NEVER had one behave poorly or show aggression (without justification) toward anyone..We have a 5yr old male that has started to growl and show signs of aggression at the drop of a hat. He can walk into the room take one look at my wife and growl,show teeth,hair up,ears back etc. Has even lunged at her from time to time.Needless to say we are concerned.he has NEVER been bred, but still "in tact". Wife takes him for walks ,plays with him and has never treated him other than the wonderful dog he is.WHY has he started to do this?? Wife is becoming terrified with the thought of being alone in the house with him..Our breeder said it is due to him not being neutered,I am not so sure.We love this dog and are very worried about this....HELP!!