my yr. old hen is sick, her comb is flopped over, very dirty vent,lots of discharge, i got her out to check her, & clean her, there was a round small mass at her vent, i went to get it off of her, but it was "attached" by a strong fiber like thread, so i lubed all around with hemmoroid ointment & vaseline but could not budge this thing, vent is very red & swollen, the mass is about the size of a large marble, what could be wrong with her??