Xylitol. It's made from a birch bark extract. I only learned the specifics after I caught my pup having dug an empty pint of Rebel out of the trash and lost it.

Xylitol. It's made from a birch bark extract. I only learned the specifics after I caught my pup having dug an empty pint of Rebel out of the trash and lost it. Then I looked up the info online. Some sweeteners will upset their stomachs, but Xylitol will kill them.