hi,

we have that problem with our older golden. we have tried everything possible to stop her from scratching bitting...ect..
her problem is a combination between habit and allergies. once we fixed the allergy portion we are now working on the Habit part.

what we do now to prevent her from doing it is we have a spray bottle with plain water in it. and if she starts we spray her once and say NO. and if she continues we do it again..
ususally we only have to do it once to make her stop. the inital squirt usually distracts her from what she is doing.
i have read that the spray works because the dog usually doesnt understand that YOU are the one spraying them so eventally they combine the spray with the command NO and you can wean off the water and just say no.

also she gets bored really easily so we make sure we have toys for her to chew on instead of herself.

also we have some stuff i cant remember the name right now but it is a spray that we spray on her that doesnt hurt or sting or anything that makes her not itch anymore...so it is habit not allergys.

i have also read the more attention you pay to them when they are doing it the more they will continue....example if you start talking in 'baby' talk when they are doing it. they feel rewarded and will continue to do it. where as with the simple command NO they get that they arent supposed to do it!

just some suggestings
take what ya need and throw out the rest

Manyinone