I did a quick search but did not see a treat specifically made for kongs. I use to make a "pupsicle" out of yogurt and peanut butter, I'm assuming that will work and possibly be healthy at the same time. I would love more suggestions(or a different one if that does not sound like a good idea) I was also considering a ground tripe/trachea mix to freeze inside. I am still trying to work out treats to balance with the meals. Thank you!