A friend of mine recently expressed some exasperation that her 10 month-old puppy suddenly seemed to forget everything he had learned and was actively resisting training. I asked her what she was like when she was an adolescent. My friend’s dog is somewhere in the adolescent or juvenile stage, and is being a brat. Its just a good thing he’s cute.
Like us, dogs go through stages of emotional and physical development, and their behavior changes during those phases. Here’s an excellent brief on the subject, courtesy of the Arizona Humane Society.