we get a bag of dog food
from wal-mart called dinner rounds, i think there by o'royal, not sure. but they are large, and kind of soft, they make great treats for Allie, either alone or stuffed into her kong, we get the smaller kongs for her, and we can fit about 3 or 4 in at a time, depending how much effort we want to take to put them in
its not her normal dog food, so she likes them, but it is just dog food, so we dont feel guilty if we give her a few too many sometimes.
or else we put peanut butter int he bottem to plug the hole, then fill it with water and freeze it. this is a bit messy, but she likes it.