Sounds to me like they have a Respiratory problem. I am having the same thing, you must act quickly! I have already lost 3 of my laying hens and have 2 in Isolation. I give 2 tablespoons of Sulmet (sulfur) in a gallon of drinking water. Unfortunately It came on so fast, by the time I recognize what was going on, I had already lost the hens And it was just a matter of 2 days. So today I put all the chickens outside, then pulled everything out of the barn, scrubbed and bleached their waterers and feeders. Took all the shavings that I had just put into the shed 2 weeks ago out of the shed, then I sprayed all cracks and crevices with PD44, Then I let a Bomb off keeping the doors closed for 2 hours to kill any mites or lice,( I usually do this twice a year) then opened up the shed to air out, replace shavings, water,feed.
A Thing to Remember when giving medication to your chickens, especially to your laying hens, DO NOT SELL OR EAT THE EGGS FOR AT LEAST 3 WEEKS AFTER MEDICATION HAS BEEN GIVEN!
Chickens need a dry, warm, clean enviroment, draft free from cold winds and rain.
I think my problem started, when the weather here went from 70 degrees down to 40 degree, Rainy, wet cold wind blown rain, it was like that for 2 weeks! Evne though I had my chickens in their shed during those days, just the dampness set in. I now am running Lamps with 60 watt bulbs and a 250 watt heat lamp. I usually don't run these till the end of december, that goes to show you how the weather has been.
I am praying that my 2 hens make it through this, I've already lost enough! It is Heartbreaking!
I wish you the best and I hope this has helped you!
Anyone else having this sort of problem?
Websites for Respiratory Diseases:
http://www.veterinaryworld.org/Vol.1 No.7 Full Text/Common Respiratory Diseases of Poultry.pdf