Well this update is not so good.
I thought they were starting to look better, but...
I went out to the coop yesterday when I got home from work to close them up. When I came back around and went inside the coop, I saw right away that my BLR Wyandotte cockerel was laying there dead. He was frozen a bit, because it is chilly here, but the others also picked at him a little, too.
Then this morning, I cheerfully spread the food out in the run and then let the stampede out. I could just tell that they didn't all come out, which was really unusual. Sure enough, with my head sunken, I went into the coop and found a BLR pullet dead, also pecked a bit.
Between Sebrights and BLR Wyandottes, I only have one left of each. They seem to be the only ones that are dying! The only connection I can make with that is this:
When they were little, I kept them in a rabbit cage together. I refreshed with hay every couple days, but out of nowhere, it was matted down terribly with poo and they were really lethargic for a couple days after that. They are both 20+ weeks but they are not nearly as heavy as I thought they'd be. Maybe that had something to do with this whole thing.
Because now that I think of it, besides some runny noses and a couple sneezes, these two breeds are the only ones I've had trouble with...and they were together as babies, even when they got sick.
Maybe they have had a respiratory infection this whole time and they just didn't show signs?
They have had a lamp now for a couple weeks like people around me and on here suggested. I'm thinking about adding another for the coldest nights of the season coming up, but I'll have to figure that whole mess out.
Any thought would be appreciated. :/