We have 100 barnyard chickens, and Ginnys. Various types , Rhode Island Reds, Yellow Buff Orpington, Aruacana, Ameruacana, Dominiker. All Range free during the day on a small farm in southeastern Oklahoma. Fed hen scratch, and chick starter. Most are incubated to hatch. Recently 6 young Rhode Island Reds, and Yellow Buff Orpingtons ranging in age from ( 2 to 4 weeks ) have shown symptoms of gasping for breath, and yellow mucus discharge, that runs and mats up on the eyes . 2 have died seemingly drying up , dehydrated. As a preventive we have occasionlly mixed 1 teaspoon of terramycin / gallon of water. And have started giving vitamins yesterday, 31 May 2011. We are keeping the symptom birds quarantined, in a small cage. All assistance and information is greatly appreciated.