Hen with a never-ending cold?

[cinnamongirl]

I've got 2 one year old frizzle-cochins that I've had for about a month and a half now. When i got them, I didn't notice any health issues. One had a bald butt, but they had been penned in with a roo so we assumed it was from him. I had just finished my coop and moved my 3 month old girls out there, but there wasn't room to keep the newer girls isolated from the others for the required 30 days so they stayed in the house in a dog kennel. The next day I noticed one was blowing snot bubbles

(the one with the bald butt). I separated her from the other into another kennel. I've given her polyvisol which she actually takes voluntarily and put vet rx in her water and over/in her beak every day. She's eating perfectly fine...maybe even a little more than her sister. Drinking plenty. She's behaving normally. Doesn't have to breathe through her mouth. Her eyes are clear. Poo looks like everyone else's. Other than the occasional boogie you'd never know there was anything wrong with her. She used to sneeze every now and then, but at least that's gone. Since giving her the vet rx, when I check her nose it's usually crusted and when I remove it, there's fresh clear mucus behind it. Her sister never showed any problems, but she's still quarantined because she turned out to be the feather picker. She wouldn't let the others eat when I put her out in the coop. So now almost 2 months later, I still have two house chickens. I'm hoping that putting them out together will keep the one from feeling like she has to be a bully to the younger ones, but I'm afraid to do that until we get this cleared up.
Everything I've read seemed to shout "doom and gloom" about chickens with colds but this seems way too minor to cull her. At first I thought maybe it was the air conditioning that she wasn't used to, so I covered her kennel with a blanket and only left the door uncovered but made sure there was no draft. Maybe it's because of her bald tushie that she's always got her own sort of draft? But since it has gotten colder, we've not had the air on and had the heat on only a few days. Is there such a thing as an "adinoidal chicken"? You know...like there's always that one kid who always has a runny nose? Or allergies? Am I just not being patient enough or is it a lost cause? Any ideas? Thanks in advance for any input!

 

[farmin'chick]

Are you feeding her a feed that has lots of "dusty" type particles, or is she in a dusty environment? Just like us, some chickens are more sensitive to that than others. I have a perfectly healthy Buff Orp that has sneezed off and on for the last 6 months, ever since she was a young pullet. She's laying now, and is healthy, just sneezy.

 

[cinnamongirl]

We're feeding her Layer crumbles...I guess a little dusty, but not much. A little bit of oyster shells and just a 1/4 cup of scratch every other day. Pine shavings for bedding. The house isn't dusty. I do have cats and they shed on everything...maybe she's allergic to cats? lol Sounds like a healthy allergy for a chicken to have. I don't know. Seems to me that she's not actually sick, just irritated by something, maybe something inside like dust like you say, but I'm afraid to move her outside even if I were to keep her in the kennel in the shed or something because the cold weather might make it worse. Think I should try it?