Today was Lucy's fourth training class at Petsmart. She is naturally skiddish but she has done well and has been very social at every class. Today she growled and tried to advance toward two dogs in the store. She has never shown any type of aggression like this and it worried me. Today she was exceptionally nervous for some reason. We have had terrible weather here and she has not been able to romp and run like normal. Do you all think it may have been the inability to release all the energy? Or like Cesar says, it was me projecting the tension??? Help! I one thing is that she needs to build her confidence - any suggestions?