Be very careful dear friends of ours lost a great show dog English Setter to this only late last year.
They are still greiving to this day and have owned and bred dogs for over 40 years.
Very experienced exhibitiors and dog people.
Dog was about 18 months old. :D
So it is not just puppies who do this, he ate it out of the blue had not ever eaten a rock before.
Stone caused a blockage in stomach, he died at the vet overnight.
But in saying this we cannot watch them 27/7 terrible things happen all the time even with the best of measures.
Malisa