1) What type of bird , age and weight (does the chicken seem or feel lighter or thinner than the others.) 5 months, sussex 2) What is the behavior, exactly. Rattly sound, worse at night, shakes head, sneeze 3) How long has the bird been exhibiting symptoms? 3 weeks 4) Are other birds exhibiting the same symptoms? 3 roosters but we chopped them today, same age. Has had all of them since 3 weeks old. 5) Is there any bleeding, injury, broken bones or other sign of trauma. No 6) What happened, if anything that you know of, that may have caused the situation. 7) What has the bird been eating and drinking, if at all. Eating and drinking. Norwegian starter feed that is used until hens starts laying eggs. 8) How does the poop look? Normal? Bloody? Runny? etc. From pictures i have found online it seems all poop is within normal. 9) What has been the treatment you have administered so far? Vitamin mixture in water for 3 days. 10 ) What is your intent as far as treatment? For example, do you want to treat completely yourself, or do you need help in stabilizing the bird til you can get to a vet? Treat or chop, so we will try to treat first. 11) If you have a picture of the wound or condition, please post it. It may help. Have found a film on youtube with same breath.. 12) Describe the housing/bedding in use. Housing is a large "box"/room built for a horse, temperature is around 15°c 24/7, light is about 10-11 hours, bedding is "chipped" tree(sorry about my limited english vokabulary/spelling), so not shaving or dust. There is ventilation but the air is still moist, not found a solution to reduce that moist so far. This hen has not been free range so far since temperature dropped when she was 8 weeks. It is -15°c outdoors and + 15°c in the coop, so some cold air gets in when we clean coop and when we go in and out. It has not been dewormed. The other chickens (other breeds) has not shown any of the symptoms so far. There are other chickens in same box and another box next to this one. They have plenty of space in their boxes. Any advice on how to treat this hen?think it's going to spread to the others as time goes? Happy new year!