Hen has a swollen eye, yellowish mass covering her cornea, oozing clear, slimy fluid. Seems painful to her when I try to clean it. Any help in identifying what would cause these symptoms, and treatment advice is much appreciated.
Welcome to BYC. Do you have any pictures? Can you describe any symptoms, such as nasal drainage, sneezing or coughing, wheezing, or shortness of breath? The eye cough be a sign of coryza, a respiratory disease. But it also could be an eye infection from a peck to the eye, or from dirt or an unknown irritant in the eye.
I would try to squeeze out or clean out any pus or gunk in the eye by applying wet warm compresses, using QTips to dig it out. Get some Terramycin eye ointment from your feed store and apply it twice a daily to the cleaned eye.
If you suspect a respiratory infection, I would also get some Tylan 50 injectable, and give it orally.