Baytril is banned for poultry, but many vets will still prescribe it. If you explain that this is a pet and not kept for egg production or for meat, that may help.
Most research into poultry is geared toward commercial production of eggs and meat. Those birds have relatively short lives, meat birds are processed very young, laying hens are culled when laying tapers off. Not a lot of research into keeping chickens as pets and into old age. The interest in keeping backyard chickens has outpaced the bureaucracy and avian vets are a specialty that is in short supply, and some of those are not interested in chickens. Many people don't have access to a vet that will even discuss a chicken. I wish you luck with her, but understand you may not have success even with treatment. I don't question your wish to try, at all.
Most research into poultry is geared toward commercial production of eggs and meat. Those birds have relatively short lives, meat birds are processed very young, laying hens are culled when laying tapers off. Not a lot of research into keeping chickens as pets and into old age. The interest in keeping backyard chickens has outpaced the bureaucracy and avian vets are a specialty that is in short supply, and some of those are not interested in chickens. Many people don't have access to a vet that will even discuss a chicken. I wish you luck with her, but understand you may not have success even with treatment. I don't question your wish to try, at all.