Yes, some diseases can come from wild birds. I would probably use the Tylan soluble powder or the oxytetracycline in the water since there are more than one, but some feed stores may not stock all of these, or have the small bottle of Tylan (the large one can be expensive.) The oxytetracycline may have different brand names, but I think Terramycin is one of them. Others you can use if you can't find these is gallimycin (erythromycin) and spectinomycin or Lincomycin. These are listed in the link I sent you. If they get bad, Tylan 50 injectable is the way to go--it can be given as a shot in the breast or orally (very carefully so they don't choke.)