Body Functions Trace minerals play a variety of roles in all your dog's body functions. Unfortunately, trace minerals are typically deficient in the average dog's diet. This is due to the fact that most farm soils are deficient in trace minerals. Therefore, the plants don't contain the needed trace minerals. The trace mineral deficient plants and grains are fed to the farm animals like pigs, cows and chickens. Which in turn are fed in part to our dogs. But you are what you eat, and in this case, trace mineral deficient. This is bad news for your dog.