I noticed today that my light brahma who is 15 weeks old had one if her eyes shut. She has always been smaller than my other brahma hen and always a little paler. She was laying in the shade when I noticed. I picked her up and stared at for while and she didn't open her eye. When I put her down however she did open the one bad eye for a few seconds and it looked fine. I know coryza involves puss that smells disgusting but I put her eye right up to my nose and it had no smell. Wednesday, which was now 5 days ago, my rooster pecked her in the eye but she seemed alright. Is she closing her eye simply because it is scratched or is this the very start of coryza? I have already separated her as a precaution. I also already have Sulfadimethoxine on hand (Storey's Guide To Raising Poultry says that this is the best medicine to treat coryza.) Should I start her on it immediately or wait a day or two to see if it is just a scratch?