Sudden rumbling in chest, gasping, sneezing chickens? Best antibiotic?

[Liza728w]

She's on day 3 of full dose baytril, no improvements. Poor girl, I was really hoping it would work. She squeaks and still acts lethargic. She just had a sneezing fit a second ago. She's definitely drinking it, so it looks like it's getting in her just fine.

Thinking about finding a place to do testing where I can send in some samples.

Tractor supply does have LA200, wondering if I should try that after she finishes the round of Baytril.