My poor black sex link has been sneezing for 2 1/2 weeks. She wasn't showing any other signs until today when I let her out of the coop. One side of her face is swollen. There is a membrane that is completely covering her eye. She now has an eye discharge and a nasal discharge. I took her to the local vet (who admitted he didn't see too many chickens) and he found her to be very thin. (I'm new to chickens so I didn't know anything was wrong!) He put her on cephalexin twice a day. I'm just wondering if anyone has any experience with this particular antibiotic or if I should use something else for this particular infection. Also, should I treat all the other birds in my flock with antibiotics? Thanks for any input.