Butch does the reverse sneeze (never have figured out why they call it that!) when he gets excited. My other chi mix did the same thing. If it goes on for more than a couple of snorts, I just pet him and calm him down. It usually works.
But a vet visit is a good idea if you are concerned about it.
Good luck! It can be a scary sound though. It sounds more like an asthma attack to me.
