Posted: 29/10/2012 at 12:03
Slugs will strip bark at ground level, but I suspect that such widescale damage is an animal of some sort, possibly a cat, dog or squirrel. It's not common, but animals can sometimes get strange obsessions.
Stripped stems won't survive, so you may as well trim them down to ground level; new ones will grow next year. Make sure that you protect the new growth from slugs in spring, and protect the shoots higher by constructing a tube of chicken wire that surrounds the new shoots - that should stop problems from animals.