I have a baby chick that is sick with some sort of URI. Symptoms began with watery eyes and discharge from her nostrils. She also would open and close her mouth as if she had trouble breathing. I started her on tetracycline in her water 4 days ago. At first, she seemed to improve with eyes seemingly watering less and less discharge from her nostrils. She has continued to eat and drink and be active. This morning I came in to feed her and she had raspy sounds when she breathed. It sounds like mucous is in there and it sounds kind of gurgle-y. It almost sounds like she is sneezing from time to time but I'm not sure what a chicken sneeze is supposed to sound like. Should I start her on Tylan instead? I'm so new to chickens and am unsure of what steps to take. I have also been rubbing VetRx on her beak each night before bed.