BarknBig Beef 6" Marrow. Marrow Marrow Marrow - it's so lucrative to our pets who need fat in their diet. We all know there is good fat and bad fat. Marrow is good fat that helps their skin and coat. It adds nutrition to their diet that they don't necessarily get from their kibble. When your dog gets addicted by the marrow and they are an aggressive chewer you may notice tiny little pieces chipped off of the ends of the bone. That is completely normal. If you notice major pieces missing, we recommend taking the bone away and upgrade to the shin bone for aggressive chewers. It is your responsibility to know if your dog is a very aggressive chewer. Marrow bones are geared toward mid-aggressive chewers not for savagely aggressive chewers. If your dog can handle it without getting overboard, this is the perfect bone for your dog.