Could it be displaced pain? You know where it hurts in one place but that isnt the cause. Or the itchy part that when you scratch it itches somewhere else, if you get what I mean lol!
Becky

Can't see the pic of her Vincent,
If you go to the 'your dogs pics' section on the forums,one of the first threads will explain how (think they have to have brackets on them,like this [IMG]whatever the code is[IMG] or something along those lines) I use photobucket so yours is probably different.
Does she do it when you're at home, when you're out or both ?
If its whilst you're at home i would try a firm 'NO' and then distract her with something else, toy etc....you have to keep on 'at it' as it may take some time.
If its whilst you're out maybe its some kind of reaction to 'seperation anxiety' again i don't know too much about this,but maybe making sure she has plenty to keep her occupied while you're out may make a little difference ?

Hi Vincent tail nibbling can also be a sign of OCD (obsessive compulsive disorder) in some breeds..

http://www.ivis.org/advances/Behavio...scher/IVIS.pdf

What do you do when she does it, try not to shout at her but distract , also make sure she has plenty of mental stimulus as well as walks, use a kong/ball that drops pieces of biscuit/ and games like hide and seek.

My Sasha, a German Shep. Mix does this whenever left in a kennel. She doesn't do it at home, so either it's a sign of separation anxiety, boredom, or stress. We keep her out of kennels now anyway, so needless to say, it's healed up!

Know that sibes will sometimes chew the tips off due to stress, anxiety as I had one that did it a few times. Normally when I went on holiday or away to work for a few days. It should grow back if this is the case although I would take her to the vet just to be sure it's not anything to do with her skin. How old is your little one? Does she have a playmate?
To stop her chewing try putting a mixture of olbas oil and teatree spray on it. Mine hated it! Gives it a chance to grow back but it does take ages.

wolfy is not tuching the tip of her tail any more she has stopt it i noteced it today and she always playing about with our other dog yorkshire terrie.

Keep an eye on her as mine went back to it after about a year. Nice news that she may be more interested with her playmate than her tail!

i will be keeping aneye on wolfy right now they both are asleep which is good new but she is a lot better now