Tessie, I wouldn't use Cheese, most of us use Peanut butter(low fat) and yogurt(plain, low fat), with a bit of banana as well...here's some other tasty things you can use...With the PB & yogurt, I pop it in the freezer for a couple hours first
KONG FILLINGS
Cheerios and peanut butter
Chunks of Apple and peanut butter
Cooked macaroni and melted (not runny) velveeta cheese
Bananas and unsweetened applesauce - freeze
Cream cheese, peanut butter, and applesauce - freeze
Applesauce with chunks of fruit - freeze
Bananas, cooked oatmeal, applesauce, and yogurt - freeze