How to get rid of odors in wood?
You can try a few things:

1) Treat with odor neutralizer.  Pet stores and hardware stores usually sell products designed to remove odors.  For set in smells this may not be 100% effective.

2) Seal the wood. If you don't intend to use this surface as a final surface, a coat of sealant style paint (Killz is my brand of preference) will not remove the odor but it will lock it in the wood so you won't smell it again.