My 3-year-old works well for the Zuke's treats and I highly recommend them. They seem to have high quality ingredients and don't cause allergy issues with my girl. We started a beginning agility class this week and she was drooling for her Zukes. I will say though, the group before me left a "Beggin' Strip" on the A-frame and Cass got it and seemed in heaven. In fact, she bolted up that A-frame each time in pure optimism that she would find another one.
Some of the "traditional" pet-store quality treats are about the equivalent of a Pop-Tart. OK in very small amounts, but not something you would want to give every day.
I also like the soft Pampered Pet treats
These are a round (about 1 inch size) soft cookie. For training I cut them in 1/4 but my pooch is small. We've tried the Pumpkin and the Peanut Butter flavors. You can mail order from Drs. Smith and Foster or Amazon.
I hope it isn't bad that she is so food obsessed. I do praise her like crazy when training, but I always feel she is sniffing the air to see if I have a treat for her.