Our little puppy has recently started showing aggressive behaviour. as a young puppy we socialized her well and her behaviour was good. recently however she has biten a few people and has become aggresive towards people she knows even. she barks consistently when walking and has to be mussled. we dont let her near other dogs now as she barks and lunges at tham yet is fine with our other dog at home. she is over protective of the home aggresively barking at anyone who comes to the door and does bite people she doesn't know if they enter the house. she is an extremely affectionate dog towards her family members and itis breaking our hearts that she is exhibiting this kind of behaviour towards others. we dont know what to do and do not want to have to send her away. please help!!!!
It sounds like your puppy has taken over the dominant role in the house, and therefore feels the need to protect the rest of 'her' pack against visitors coming to the house. You will need to re-establish yourself as the alpha dog before her aggression progresses. There are a few things that you can do to indicate to her that she is supposed to be at the bottom of the hierarchy. These include insisting that you walk ahead of her through doorways and when walking on the leash, and feeding her after you have finished your own meal. You must ignore her if she comes up to you for attention, as she has to learn that attention from you is earned and not just given out whenever she wants it. Before you pat her or play with her, give her a command, such as 'sit-stay' so that she will see that your attention is a reward for good behavior. This will act as an incentive for the future. If you are playing a game with her, make sure it is you that chooses the toy and when you decide that you have had enough, take the toy away with you so that she realizes that it is you that controls playtime. When you first come home, you should greet the rest of the household first before saying hello to her. All these things can be incorporated relatively easily into your normal daily routine, although it will require some patience and perseverance from you. She will struggle initially as she sees herself as the alpha dog and therefore being in the submissive position to you, who she sees as a subordinate, is distressing. Soon she will settle into her new place in the hierarchy and should become a more relaxed dog, as she has been relieved of the role of protector.
If she starts barking or lunging at your visitors, take her by the collar and lead her away to a 'time-out zone'. Don't speak to her or make eye contact when taking her away, so that she is getting absolutely no attention from anyone at all. Leave her there until she calms down and then make her obey a command, such as 'sit-stay', before releasing her from the 'time-out zone'. If she misbehaves again, do exactly the same. She will soon learn that that is not the way to get attention.
It is a good idea to set aside some time each day for a bit of obedience training, which will not only improve her obedience levels but also the relationship between you.
I hope this helps and all the best with your training!