sinus problem? lethargic/gaping

Hi all, new to posting but have lurked a while and always found the forums extremely useful. I have a 10 month old Speckledy who to be honest has never been right since we got her at 17 weeks. She is very timid and gets bullied by our older hen although is friendly with the other 10 month old.

She moulted about a month ago - not sure why except thinking maybe stress brought it on. She has slowly become more and more lethargic, this week her breathing is laboured and after she eats (although this morning she wouldn't eat) she gapes as if to clear her throat. She shakes her head and scratches her ear area and her eyes are half closed. Hunched with tail and wings down. She only laid 3 pullet eggs when she was 22 weeks and then stopped and hasn't laid since.

She is wormed regularly, the coop and run are cleaned daily, food is fresh, she is supposed to be fully vaccinated against all the normal things. She wolfed down a scrambled egg with probiotics yesterday. There is garlic and ACV in the water. Diatom used once a week in the coop and no signs of lice on her. The other two are fine.

My instinct is to cull - as I said she has always been poorly with something. Husband wants to keep trying with her but he isn't the one doing all the looking after. We don't want to treat with antibiotics because it seems most likely viral, and we try to avoid them. We like our hens but they are for eggs primarily. I know I should isolate her but am worried that she won't be accepted back and we would end up culling anyway as I can't give her away.

I'm out of ideas now and to make it worse we are away at the weekend. A friend is looking after them but I don't want the hen dying on him! Is there anything else I can do?

Thanks Joyfull, I had thought to rule out mycoplasma as she she should have been vaccinated. Apparently the vaccinations don't always work? A friend has two columbines from the same place, same age and today they were showing the same symptoms so perhaps their vaccination programme didn't work well this year.

Funny you mention the smell, she does smell different, I commented on that to my husband yesterday. Sort of whiffy musty.

I can't get to a vet until Monday, is it best for my friend to feed her mealworm and egg over the weekend? She won't eat pellets :-(

Thanks for your help.

Thanks again Joyfull, unfortunately she went downhill really badly. I was away but my husband had her isolated in the warm, hand fed her scrambled egg and mealworm and got some antibiotics into her but by the time I got back last night at 11pm we both knew it was unfair to let her struggle on. As I said previously, she had never really been well and her nervous disposition (probably caused by underlying illness) meant that she was never a happy hen and probably would never be.

 It has been a learning curve, particularly with regards to antibiotics. Although I still disagree with their use in most poultry I can really see why people use them as all we really want is the best for our birds. BTW my stance on them is not selfish, I have personally turned them down from my GP before for my own use! I am glad to see that they are being prescribed more carefully and much less than previous years and I hope I don't have to use them again (but maybe would which is a bit of a U-turn for me)

Keeping a close eye on the other birds now. There seems to be a lot of respiratory stuff going round at the minute coinciding with the very late arrival of many migrating birds here in the NE. Hoping we don't get anything too serious and keeping a close eye on my other birds now.