If you want the "reality-based" answer, I have no idea.
If you want the pure game-mechanics answer, then YES, they definately have opposable thumbs, because nowhere in their description does it state they cannot use tools or learn skills that require hands. It does say they have claws, and if memory serves, they have a Dex penalty (-2?) so presumably their hands are clumsier than human ones.
This viewpoint doesn't hold for various non-PC races/species. For example, nowhere does it state that a normal wolf can't use tools or learn skills that require hands, either, but for PC races/species, I'll hold that as an absolute.