Hooves, marrow bones, knuckles and ostrich bone. The hardest things in the shop, and the longest lasting by some distance.
For a confident adult chewer only. Not for a puppy, not for an older dog with worn teeth, and not for any dog that has fractured a tooth before.
Everything here is air dried or raw dried, never cooked. Cooked bone splinters, which is the single piece of dog advice almost everyone has heard and it is correct.
Marrow is the draw and also the catch. It is rich, so a dog with a delicate stomach should get a little and not a lot, and a filled bone goes further than an empty one.
Supervise, and take the bone away once it is chipped or small enough to swallow. A hoof that has split into a shard is done, however much life looks left in it.
Smell and mess: the messy end of the shop. Marrow is greasy and will mark a carpet, so this is outdoor or on-a-mat territory.
For how they compare with everything else that goes the distance, read long lasting dog chews.