Smilla, I would love to see Lefty munching on those berries!!! I think with things like that, a little probably goes a long way, but I have no real basis for that thought. I'd just give him a little at a time. That way it will always be a special treat for him!!!!

I just remembered when I re-read your post that grapes in large quantities can be toxic for dogs, so I would definitely use those sparingly. My Lilly loves them too.