We have just returned home with the gang after having a walk that we don't often do. The Hazel trees were absolutely covered with nuts, some were quiet huge and ready for picking. As we picked them, quiet a few of the other ripe ones that were ready for picking were falling below, (just where the girls were waiting). The girls already know about Hazel nuts as we have some in our field, so as fast as the ripe ones fell onto the ground there were dogs waiting to snatch them up. Just a few crunches of the nuts to break the shells and the whole things were swallowed. I have never noticed the nut shells pass through the dogs in the poos and they have never caused a problem. I suppose that if the shells turn brown within the digestive system, they would not be easy to distinguish. As dogs don't have teeth for grinding, I wonder if their digestive systems can somehow digest the nut shells ! I am not going to soften their poo on a bucket of water to see what the nut shells look like after they have passed through. hmm. .