Gourmet Blends contain one or two proteins, consisting of 65% muscle meat 10% tripe (muscle meat), 10% organ meat, 10% ground bone, and 5% mix of kale, spinach and kelpPure Formulas contain 80% muscle meat, 10% organ meat, and 10% ground bone with no added vegetables. Pure Formulas are great for dogs with allergies or for doing an elimination diet. It also gives you the option to add any additional items that your pet may require.Specialty Blends are a mix of two proteins. Our Chicken & Lamb and Performance Blends both contain tripe; the Turkey and Salmon Blend has nothing added.