Read Rickj's link. Unfortunately Greenies aren't the only problem. See
https://www.askmehelpdesk.com/dogs/dog-toys-42979.html There I point out the danger of a dog gnawing down a suitable size chew to a dangerously small one. And of course, they can tear off pieces of rawhide, squeaky toys, stuffed toys, etc. The pets stores are full of that stuff, and apparently many dogs do fine with them. Dogs and their chewing vary. The Lab I had last year, I think did more damage to our Kongs than the other 16 put together.
Year ago on the original AskMe.com, one member I knew and trusted posted a heart wrenching description of watching her dog choke on a Greenie.