Dry pox is not normally a problem in adult hens. Its the wet one when lesions get in the mouth that is really nasty. It usually looks heaps worse than it is. One of my Japs had a really bad case that took weeks to clear up but it was the dry pox & she was fine. Just keep a good eye on her & separate her if you haven't already as it's quite contagious if your flock hasn't been immunised.How do i know if its severe? What are the symptoms of a very severe case? And what are the chances of my hen surviving