I give my buns applewood sticks....Peppy gets thestore bought kind because Toronto has no trees lol and Maggie gets theones off the apple tree in the back yard.
I always assume most trees were okay for them...except maybe Maple trees because they have icky syrupy sap stuff in them :?
Neither of the two sources I look to forquestions like this indicate whether walnut is safe or not.Here is the online source I use. Scroll down to the area youare interested in.http://earthhome.tripod.com/rabsafe.html
MY other source is a book entitled, The New RabbitHandbook, which has a pretty comprehensive list of safe andnon-safe items. The fact it is mentioned in neither sourcewould preclude me from using it, unless someone were to provide somecontradictory information I could rely upon.