Hi, I would like some help please. I have 1 hen who has been gaping, has a rattling sound when breathing and is shaking head. Comb may be a bit enlarged a bit puffy at end.( I may be imagining this as she has always had a large comb, she is a cream leg bar) No discharge that I have noticed either from rear or beak, eyes appear clear and bright she was laying up to a couple of days ago. I have treated with flubenvent as instructed but to dry pellets. Did it for recommended 7 days, no improvement. Have felt down her neck, there is a small lump about an inch from the back of her beak (under side) have compared with another hen and definitely no lump on her. Have I not managed to get enough mixture in her? or is it something else. She is still walking about and eating, but not as she usually does, she's become less lively she is usually the very bossy one, more like a cockerel. I've started another round of flubenvent, but don't think she is eating enough for it to work. No other hens are affected. She is about 6 , not sure of exact age as she was passed on to me, I have had her a couple of years now. Would be grateful for any suggestions, feel time is running out for her.