This isn't a fancy treat but Rey is crazy about it right now. I just cut some carrots into thick rounds, steamed them until they were tender, rinsed them with cold water, put them in a ziplock bag and then sprinkled some chicken bouillion and parsley flakes (for fresh breath, hee hee) on top. I keep the bag in the fridge.
I'm sure I'll be using a lot more carrots since I came home from the grocery store with a 25 lb bag. That's a BIG bag! I love fresh carrot juice though and the horses love carrots. It barely fits in the fridge, but it was only $5.99 (it's all the crooked and forked ones!).