Cathie tossed a leftover salad into WalkingRock today. It had lots of pretty green leafy lettuse (2 or 3 types) some carrots, cucumbers,brocholi and some mushrooms, NO Dressing! he gobbled it down with a quickness... as an afterthought I looked up Portabello mushroom for edibility and found nothing. Are they edible for Sulcatas?