In case you were unaware: Micotil can kill a human. It is also prescription only drug, so your veterinarian should be able to tell you if they recommend one day or multiple doses.
I think you made the right "diagnosis" but you should call and get advice from a veterinarian as to what drug is working best in your area.
Draxxin, Nuflor, Nuflor Gold, Baytril are just a few antibiotics of choice.