Help! Trying to find cheap but healthy dog food.Help! Trying to find cheap but healthy dog food. We have an over weight 10 year old black lab that must have a special food to watch her weight gain and we have a 2 year old German Shepherd that is on adult dog food. Any suggestions? The town I like in has a Costco , tractor supply store, and a few random feed stores. What is the cheapest but healthy brand of dog food? Thanks