Advise Please on Dog Behaviour

A friend of mine has a 6 month white german shepherd pup.

Pup was well socialised, lead trained, etc then suddenly out of the blue starts going crazy, chasing the postman, knocking over his water bowl at night, showing dominance towards other dogs.

She has been socialized but then takes a mind of her own and does what she wants.
He cannot get her to settle she obeys teh owner whilst on a lead- then bonkers!

The only dogs she gets on well with are larger dogs, as she cannot domiante them.

Can anyone shed some light on this?

Yup - this sounds about right. This is the age when most GSD`s begin to land in Rescue. You have to grit your teeth, go back to basics, be firm but fair and wait for her to grow out of the Kevin stage. Commiserating with other GSD owners makes you feel a lot better - why not look for a GSD club?
If not - remember it`s all about Growing Up. She`s finding out what she can and can`t get away with. Positive methods will help you end up with a well-balanced dog, so please don`t get heavy with her. Reward the positive, try to prevent the negative. It will get better.

Totally agree, she's at that Kevin stage!! Oh I remember it well!!! The ONLY thing that worked for me was to fold my arms, look up to the sky, turn around if I had to, and ignore her, that made her sit up and stop her stupid behaviour!!!! Luckily for me, out of 3 pups, the one I recently lost was the only one who went through this stage, a right miss bossy boots she was! Your friend will get there, eventually! Do you think she's been spoilt coz she's such a cute little puppy? If so, this is not the time to spoil them, wait until they're old enough to warrant it and have learned a bit of respect!!! She'll walk all over them if they don't clamp down on her now I'm afraid, so tell them to stop spoiling her IF they are!!! Good luck!

Kismet is still having fits of the bossys! She's 10 months now, but she certainly started it at 6 months.. It's like a sort of condensed teenage, they do get through it... Just remember they are all hormones, itchy teeth and growing pains and don't know where anything is or what to do with it. She'll need a firm hand and some outlets for her mad hormonal aggressive spurts. Chew toys, (A plastic bottle with kibble in or a knotted towel filled with kibble are Kismet's faves)

I lock her away from the others when she gets a strop on so they don't get dragged into it and give her stuff to vent it all on, or take her into the garden on her own for a good game of tuggy, making sure I win more often than I lose and she's never allowed to bite me, just the toy.

Selkie calmed down and settled out of it when she got to about 2, I live in hope with miss stroppy boots Kismet though Tell them they're not alone and get them on here for some sympathy!

Oh dear teenage hormones and behaviour. As long as your friend stays positive with the dog, does not skimp on the rewards but increases them insted and take every opportunity to praise her and practice practice practice both with distractions and with out.

Tonks is very well socialised and is well trained (even if i do say so myself) but given half the chance, she will still lie on little puppied. No growling, mouthing but just lies on them. She did it tonight to the neighbours new 10 week old puppy. I give her once chance to play nicely, and if she wont she calmy goes back on lead. She is fine with older puppies and dogs.