My flatcoated retriever has a very sensitive stomach so I have to be careful what I give him but these don't affect him at all and he spends hours enjoying these marrowbones.
I was very excited to get these, thinking that the bone would stay in tact (for a while at least) and my dogs would have fun chewing on them and getting the goodness from the middle. As soon as one of my bigger dogs got a hold of one of these the bone splintered - which is very dangerous. They might be more suitable for smaller dogs. I will get them raw from a butcher next time.
Really good toys
My elderly Collie has great fun with these chews even my kittens have a go at them