Carpeting? Then, this is bone for you! Even after the marrow is gone, our marrow bone lasts a long time. Your dog may treat as a toy and continue to play with, or grind on, it long after the marrow has been consumed. Marrow bones are the highest in the fat and nutrients of all our raw bones. All bones contain marrow; however, marrow isn't bone. It’s comprised primarily of fat and blood components, a key component of the lymphatic system and essential to supporting your dog’s immune system. Each package weighs approximately 1-lb.