I have four birds in my flock, two production reds and two barred rocks. Today as I was letting them out of their run that one seemed to be moving slower than the others. Typically when I let them out I stand there and they hesitate before the walk through the door and make a run for it past me so I don't try to pick them up or inspect them. Today the last bird hesitated a beat too long and when she got through the door shew didn't really start running, she just picked up her pace a little. When I picked her up and looked at her closely I could hear her breathing - nothing to indicate fluid in the lungs, just an audible breathing sound. I've checked 2 of the three others and I hear no breathing sounds. I'll check the other in a minute. Is there any way to differentiate between the possible causes of breathing problems, such as a cold, a virus, or whatnot? I guess you could add a little lethargy to the equation, though she is eating normally. I have Valbazen, Wazine and Ivermectin, but I ran out of Tetracycline. Is there anything over the counter besides electrolytes and vitamins (which I have) that I can give her, should I wait it out a couple days to look for more or worsening symptoms, or go get some form of treatment now? I will separate her from the others today.