I wouldn't dream of using Baytril and vaccinating. We use too much gear propping them up, keep too many stock pigeons, and don't push 'em far eneough.
I use cider vinegar and honey, natural yoghurt, and milton. I do treat for kanker and use Ivermectin for worms, but this is only occasional. When young, the birds need to establish their own immunity first, before treating with all and sundry. The overuse of drugs, in the livestock industry, has caused tremendous problems, and it's not a road I wish to go down.