We are a family of 4 and have recently gotten our first German Shepherd Puppy. Her name is Leia and she will be 18 weeks this Sunday (17 June). Ever since we got her she would bite us while she was playing and we immediately distract her with a toy or a treat to stop her from biting us.
She only bites when we are playing with her or she is very energetic. We never play with our hands, we only ever use chew toys to play. I have started leaving the room for about 20 seconds if she does bite me.
However, we have just found out that she should have stopped biting us before she reached 16 weeks and are now concerned.
Is there any advice that can be given to try and prevent her from biting as soon as possible?
I would not leave the room if the dog bites. That breaks the communication and GSDs are all about communication. Why did you leave, anyway? The dog may have no clue. The dog needs to clearly understand that your reaction is tied to his behavior.
If the dog did not respond to "Ow! No bites!" I would take immediate physical control of the dog so they couldn't do it again and make it clear that play time is over and they are under my complete physical control until the biting stops. No punishment, no pain, just immediate "Can't do that!"
If I have to, I will pin them to the ground to stop the play and hold their muzzle until they get the point. Then slowly release them, making sure they stay under control, giving them lots of hugs and affection for gentle behavior. Kisses get hugs, bites get you pinned to the floor (again).
I never walk away from them. In fact, I would probably spend more time on the floor playing with them, just for extra lessons and so they have more experience with my microsignals. Remember that GSDs pretty much live to please you.
I rarely use toys to play with them. It is usually all just contact with the hands. I cannot get them to put their teeth on me any time at all. They know it hurts me so they just don't do it, even accidentally.
I only play a dog expert on the internet, but it has always worked for me in 30 days or less.