Smudge eats C/D (a prescription food to prevent crystals) but he does enjoy treats! He likes Kitty Kaviar (bonito flakes) sprinkled on his canned food, but his favorite treat is vitamin E. I found out by trying to put it on an allergy ouchie on his face, but he made it very clear that where it belongs is right on his tongue! So I looked it up, and it's totally safe, so when he hears me rattling my vitamin bottles in the morning, he trots into the kitchen and purrs for his treat. I just puncture the capsule with a pushpin and squeeze it out onto my finger, and he licks it off, purring like it's melted butter!