Chicken not foraging, falling asleep randomly

[oystercrackers]

One of my 1 year old chickens suddenly started to fall asleep randomly a few days ago. She has not been laying or foraging much, either. She has always been smaller and lighter as the others but just as healthy. I use Pine shavings as bedding for them and I cleaned the coop recently. The entire flock has discharge and we're sneezing a few days ago, but it has been cleared up. She herself does not have any discharge coming from her nose, either. I haven't noticed anything wrong with her poop. We recently introduced three new pullets but they were all vaccinated and didn't appear to be sick. I don't know what's going on with her.

 

[chickenlittle21]

Do you know exactly what the sneezing and discharge was? A certain virus? It might be an after effect.

 

[oystercrackers]

It may have been Ammonia from before we cleaned the coop. I suspected it was a respiratory disease, but I'm not sure.