If you can't get Corid, Sulmet will work. It is a little harder on their systems, but won't harm them. Just give them some unflavored yogurt with it, wether you get Corid or Sulmet, to keep their systems full of good bacteria. (my chicks have either Cocci or Coryza, so I'm learning as well. I do know that Sulmet will work for Cocci though.