alright so I have decided to use a harness to walk my dog instead of just her collar since she would get over excited pull on her hind legs and i was afraid of her slipping her collar or hurting her neck but now i have a new issue the harness is wonderfull dont get me wrong she barelly pulls with it on only when we come out of the house but she has a problem when she decides to grab onto the leash and play tug she knows the command drop but will not do it she is a few weeks away from being a year old so shes pretty strong and I only weigh about a hundred pounds you get the idea she tugs when i say drop she dosent i try and pry it from her mouth she growls and jumps all over me i try and block her and it only gets worse she will keep going with the growling and snarling im afraid im only 17 and sometimes it's hard to keep her under control i take her for at least one walk every day sometimes two so i dont understand why she is behaving this way.please help.