I recently got 3 6-mos old chickens from a friend to add to my 5 other hens. The next day after I got them I realized that one of them has a little bit of clear/slightly white discharge from her eyes and nose (mostly eyes). I figured if she is sick the other two I got will start showing symptoms shortly as well, so I kept all 3 in a separate (small) coop and started the three on Tetrcycline Hydrochloride. After keeping all three of for 4 days together the other 2 still seemed fine so I separated them from the one with the discharge from eyes and nose (the discharge has no smell to it so I really don't think it's coryza). I kept the sick one on Tetracycline Hydrochloride for a total of 9 days but it did not seem to do much for her. Overall she eats, drinks, does not have runny poop, does not have swollen face and stays active but after 12 days (for the past 3 days I also has been cleaning her face with Vet RX solution and giving her vitamins) her eyes still produce some clear gooey discharge and she still has a little bit of white/slightly yellow discharge from her nose. I called my friend that I got these three chickens from and she says that none of her other chickens have the same symptoms. Can anyone tell me what it may be? Is it safe to assume that what she has is not contagious to my other chickens since the other 2 that came with her and shared her food and water for 4 days still show no symptoms? Can chickens have allergies? I appreciate all suggestions. Thank you all in advance.