Barley is a cereal grain that is high in fiber and easily digested by dogs. It helps support a healthy digestive tract, and is an excellent source of vitamins A and C. It may be used in ground or pearled form.
Vegetable glycerin, also known as glycerol, is made from vegetable oil. It helps keep foods moist and is a more natural "humectant" than those such as propylene glycol. Glycerin also helps prevent microbial growth in food.