Baytril is not very effective in the treatment of respiratory infections, as it does not penetrate the tissue of the lungs very well.
Tylosin, or Tylan, is not very effective for the treatment of respiratory infections either, though it is known to be very effective for it antiflammatory properties, especially within the large intestine, and is widely used to treat colitis.
I have found Cephalexin to be best applied, when treating serious cases of respiratory infection.

Regards,

Jeff Snodgres
University of Arkansas
snodgresjeffreys@uams.edu
501.526.4856