My 2 1/2 week old chick has started sneezing and head shaking in the last few days. She has been alone since she hatched except for this weekend when I put three newly hatched chicks in with her. They were together no longer than 24 hours when I noticed her sneezing, so I separated them immediately. I do not think the other chicks got her sick and they are still healthy 36 hours later. I started giving her poly-vi-sol and she's had electrolytes and sulmet in her water since day 1. She is eating/drinking normally and has normal feces. She has no nasal discharge or eye goop. She is bright and alert. She has been in a plastic brooder in the house, with paper towels. I haven't used shavings with her because she just doesn't make much of a mess. There's nothing in there that would be dusty. I wash her water container with hot, soapy water every day. The sneezing/headshaking is frequent but not constant. I just want to make sure that if this is the beginning of an illness that I get it under control before she gets really sick and it's too late for treatment to help. I have aureomycin and tylan, but am not sure if this is bacterial or possibly aspergillosis. Where's the best place to start? Aureomycin in the water?