She was great, until a dog snuck up from behind us, and her switch flipped. Her hair stood up, she barked uncontrollably and nipped me in the hand as I was pulling her away (I know she didn't mean to do it, she was trying to protect us).
That's not true.
And if that's been your mindset when you have seen ANY of this inappropriate behavior then chances are, that's why it's getting worse. If you'd been able to nip it in the bud the first milli sec you saw it she'd probably still be the wonderful pup you used to have.
An untrained 9 m old puppy has NO IDEA of real 'enemies' or friends. Dogs 'sneak' up behind my dogs ALL THE TIME and my dogs ignore them. Because it's in NO way agression from the other dogs, and in no way am I or my dog in danger of DEATH from that dog who came up behind to give a quick sniff.
So, since I know my pup has no idea of a true mass murderer vs. the plumber coming to fix my sink...........................................
My dog should be looking to me, learning from me, getting guidance from ME before any type of action occurs on their part. And if I am calm and behaving like it's ok... THEN IT IS!!!!!
You need to stop thinking your pup is 'protecting' you and realize they are being rude, or bullying, or fearful and reacting because you are NOT giving them the guidance/support and feeling of security they need. If they are having to constantly come to your aid cause the world is so chock full of HORRIFYING SCARY DOGS/PEOPLE then they have a right to get more and more afraid of everything!
We have to be their leaders. We have to control situations and guide them.
The reason many of us start dog classes at 6 months old is when they are maturing and going thru different stages in the first year we are being PROACTIVE in the leadership role to guide them thru new people/places/situations. Class is full of new people, new dogs, new places. We have 'homework' during the week and then return for more classes and help.