This is a picture of my dog, dogs along with other animals and fungi contain glycogen. Glycogen is polysaccharide of glucose that is used as a storage of energy. Glycogen is produced in the liver and it is stored in the liver as well as muscle cells. Carbs are a good way to keep this energy going, a low carb diet will cause this energy storage to fall. Glycogen can be an issue if it gets too built up because it can cause dysfunction in organs such as the liver, the heart, and the kidneys.