Baytril is the probably the strongest antibiotic that backyard poultry people can get their hands on, period. Used properly there is a very good chance it will save many . I read somewhere that it starts working in 20 minutes, which seems amazing to me.
I should also mention that Baytril is one of the two *must* have antibiotics for me, the other is metronidazole. Baytril can also be used in cats and dogs for a variety of infections they can get.