Really, I think she is fine. What you are describing is pretty normal. The thing is, I am not a big believer in a lot of the doctoring recommended on this page, so take what I say with a grain of salt. It just might not be what you are comfortable with.
But I am a cattle rancher, and have had chickens for decades. Truthfully, they don't have a death wish and will eat enough for their current needs if they are able to do so. So if you have birds keeping her off feed, that is not the same thing as not eating the crumbles.
And it might be that you are overfeeding the treats, how many birds do you have? How much feed are you feeding. I don't feed 24/7. When I started I did that, and what I found was a lot of wasted feed, tread into the dirt, and it eventually stunk. And my birds got too picky about what they ate.
Now, I take down food once a day. I check it at night. If it is empty, I feed a little more the next day, and if there is left over, I feed less. I do not have wasted feed, they keep it cleaned up well. The thing I found, was they do not eat the same amount day in or day out, and very surprisingly, they really don't eat much on real cold days, even though one would think they would. Try cornbread, mine will eat cornbread. Don't bother with cornmeal mush - it freezes solid, and they won't touch it even when it thaws out. But mostly just stick to chicken food.
Sometimes, I think of it like the stomach flu, you know, for no apparent reason, you don't feel well for maybe 8 hours, and then you are fine. Sometimes, a bird will get down pin like that in very cold weather. We work outside in very cold weather, and it is amazing how going in and getting warmed up, can reset you for several more hours outside. That is what I think the vet meant. Not keep this bird inside for the rest of the winter.
People do get worried when they molt in the cold weather, it seems concerning. But again over time, watching carefully, and after all it is a normal act for chickens, it really seems to bother people more than it bothers chickens. I quit worrying about it. I might be considerably more worried if the temperatures you were talking about were -24 to -35 degrees F. To be honest to a chicken 3 degrees is not that cold, and while a lot of people worry about rapid temperature swings, birds are not mammals. Mammals do rather need to adjust their hair coat to temperatures and do so. But birds control their temperature by positioning their feathers. Plus birds have an pretty high internal temperature, and a blood vessel system that keeps the warmth of the blood internally, so to keep the body warm.
The thing is, if she is truly sick and dying, well there is not much you can do for that either. Chickens very often do not have a real long life average, some die much younger than others. It is just a fact of keeping chickens. I keep a flock of birds, but the birds themselves change over the years.
Mrs K
