Raw, frozen, beef Marrow bones.
Beef bone marrow is packed with nutrients such as phosphorus and calcium, it also contains collagen, conjugated linoleic acid, glycine and glucosamine all of which have been linked to decreased inflammation, better skin health, and improved joint function.
Feed as part of a raw, nutritionally balanced diet for working dogs.
Disclaimer: Dogs should be supervised at all times whilst feeding and always provide plenty of fresh water for your dog.