What ever happened to your chicken? What is ACV? I had two that were doing that same thing - first the sneezing - then the gasping - one became paralyzed in one leg and then got sour crop - I had to cull her. I tried Duramycin 10 for 10 days with them both (no improvement). The other is still sneezing & gasping like yours was - but is still coordinated, eating & drinking nicely - no sour crop - I too am baffled.