Do Havs do it? My Boston did, and I thought only brachycephalic dogs did it, but Indy has done what looks like to me, a reverse sneeze, a few times since I got him.
Yes, they can reverse sneeze. In fact, when Dionna did this for the first time, I had never even heard of reverse sneeze and I was very scared! I came to the forum and tried to describe what I was witnessing and was told it was a 'reverse sneeze' and also linked with some youtube videos.
She does not do it very often but it has happened.
Isabella does it occasionally when excited. I inquired about it at a vet visit and was told its just how most smaller breed dogs, even those without brachycephalic skulls, clear built up mucous from the back of their throats and nothing to worry about.