We had a sheltie who would go balistic when anyone sneezed. She would bark madly, then frantically find something to shake (typically a sock we left lying around for the purpose) and thrash the bejeezus out of it. My daughter had allergies, and sneezed a lot. The dog made the association between reaching for a Kleenex and an impending sneeze, so she would launch into her sneeze rage as soon as a hand made a move for a Kleenex, even if it was just to blow a nose.