Our supplier says, these tender morsels are sourced from USDA inspected chicken. Freeze drying is a method that removes water using pressure rather than heat, which preserves important nutrients. Chicken hearts are a nutritious organ meat and a good source of B Vitamins, Iron, Zinc, and Folate. Chicken Hearts are smaller than Duck Hearts which make them perfect for smaller breeds with little mouths! Every dog comes running when they hear the word “HEART”! Proudly made in the USA!