often when I am walking my lab she will suddenly try to take catch the lead in her mouth and turn a walk into a tug of war.  When this happens she can be very persistant.  I deal with it by telling her to sit so that I am dominant and I keep my eye contact with her and very firmly tell her "NO" but it doesn't always seem to work and often she can jump up and try to even grab the lead out of my hand once or twice I have come close to having my hand nipped.  I have noticed that it happens more on the way back from a walk in the park or the garden etc and I wonder if she is trying to tell me that she does not want to go home yet!  Can anybody tell me how I should deal with this situation and why she is doing this?
Thanks

Not sure why you need to be "dominant"?

The dog wants to play tuggy, utilise it.

I use my lead all the time for play, it is always available, is a great attention grabber and a very useful training tool

Ive just got back from training and one of the dogs was chewing the lead so the trainer sprayed it with bitter apple spray to stop him doing it. The trainer said he could weaken the lead with his teeth and one time break free, so it should be stopped using something that tastes nasty.

yes this is something i am worried about, that is a good idea, i have some clove oil that i will rub on tomorrow and see if it happens again. :-)

Tohme, how can you say utilise it?  I can't encourage a game of tug of war in the middle of the road or in the street.  The more I encourage this behaviour the more she will do it and think it is an acceptable part of a walk when it is not.  She needs to learn to walk nicely.  Particularly when she can jump up and grab the lead to the extent that she can almost grab the hand of the person walking her.
My thinking is that as dogs are pack animals and I am the leader of her pack if I get her to sit first then she is having to react to a command from the dominant leader of her pack and should hopefully then settle down.

Well it works for me.

Like anything else, put the lead play/tuggy on cue and utilise it as a reward.

However if you feel that it is inappropriate for you then by all means ignore my post.

You asked for ideas, this is one that a lot of people use.

I can't really help on this one, when i was younger i had a dobermann and as soon as we were going home after a walk he would do this, but he was very strong, and i certainly wouldn't encourage a dog to do this because it could be dangerous.  I never cracked it so i can't give you any advice, he done all his life.  I suppose it's okay encouraging a game as long as when you say stop she stops.

Warm regards Susan

Are you sure that your dog is on board with this 'dominance' idea? 

Two suggestions:

At the moment, tugging on the lead is a great way to get your attention (eye contact) and a bit of a game (you doing all that growling.)  I occasionally walk a dog who used to do this. The 'why' is always a guessing game but I think he just has lots of energy and biting and tugging feels like a suitable outlet to him.  When he did it, I would stand still, say nothing, hold however much lead I had close to my body and look away - in other words, I made myself as boring as possible so he would get fed up with the game.  When he let go, I would tell him 'good dog' and carry on with the walk.  He rarely does it with me now but if he does, he soon drops the lead when I adopt this posture.

Secondly, as you spend lots of time with this dog and it is a Lab, you might teach her to carry a soft toy back from the park so she already has something in her mouth at the time she is likely to do it.  It might also be worth considering if there is any anxiety element to this or if it is straightforwardly playful.

My Lab used to do this as a puppy, so I used to take something for him to carry instead, he was happy as long as he had something to carry, if not he wanted to carry the lead.

Once at the park he used to walk my other dog by holding her lead, it certainly used to make people smile!

We have a session at training where we encourage the dog to play with the lead, then all of a sudden we have to stop and continue with heel work, its just a case of you contolling the play :)