Issues with play biting.

To start with, I HAVE read the thread in new owners on "the bite stops here"...which is really helpful, but I have a specific situation that is concerning me. I did mention this in another thread, and the general consensus is that she will probably grow out of it to an extent, but I wanted to get as many opinions/as much advice as possible!!

Our GSD/Pyrenees puppy is now just over 3months old, and is coming along wonderfully in her training...but we are still having play bite issues. When we are relaxing in the house, we are able to work on training her bite inhibition - stopping play if she gets person along with toy, for the most part, and allowing gentle mouthing ONLY for the time being. This part isn't the issue.

The issue is that when we are out for walks, she sometimes goes for our legs - never anyone walking past, thankfully, and not in an aggressive way - its as if she gets really excited by the great walk we are on, and then tries to play with us like a bigger dog. She will leap up and bite at legs fairly hard - she has sharp little teeth, and it can be pretty sore....and I am concerned that waiting for her to "grow out of it" may be all well and good, but she is going to be a BIG girl - we can't exactly have an 8 month, 100lb puppy biting our legs!

We can't exactly walk away and leave her alone when we are on walks (obviously), so we can't do what we usually would if she bites at home.

We started off with trying "ouch/no" noises - loud noises to startle and stop her, but that just seems to get her more excited (look, the giant dog that cares for me is barking at me when I start to play! How exciting!) and then she would keep going.

Then we started trying to put her into a sit with a hand (gently) around the muzzle and saying no, and then waiting to calm down....works for that moment, but doesn't seem to stop her doing this. Same with just going into a sit and waiting for her to calm down - it'll work then and there, and we can continue the walk, but then next walk time, she's doing it again.

We've tried ignoring it, continuing to walk and pulling her head away with the leash, but not only does that not seem to work, she's nearly 30lbs already, and I'm not sure how much longer I will actually have the strength to keep her away from my legs when she is jumping full tilt at them.

Has anyone else had this problem? What can we do to stop her going at our legs on walks? Other than this, she is walking well (although stopping sometimes...being a little muley), she doesn't pull or try to get away from us.

She gets loads of excercise - between 3-5 hours of walking per day, plus some indoor playtime, so I can't imagine that she isn't getting enough. I have noticed that she is less likely to do this if she has been playing with another dog that day, but she is too young to go to the dog park, and I can't guarantee that there will always be other dogs around to romp with. I have tried doing little sprints and more energetic romps with her to get out more energy, but those end up with her going for my legs, so we basically sprint for five seconds, then sit and wait because she bit my leg. Then another five second sprint, then sit and wait. It just frustrates both of us!

Sorry for the giant post, I just wanted to give as much info as possible, because she got me pretty hard today on the back of the thigh, and I have just had it up to here with this behavior!