My 6-month old Buff Orpington started laying about 4 weeks ago and was producing a nice egg almost every day. All was well till about four days ago when she didn't come out of the nest box and stopped laying. At first I thought she was broody and when I plucked her from the nest box and put her out into the run, all seemed well. She would eat and scratch and act normal but she soon returned to the nest box. Then I wondered if she were egg bound but an internal exam gave no evidence of an egg. At this point, her poops were normal. I isolated her and put her in a large plastic dog carrier. She has stopped eating and drinking, her head is down and her hind end raised. Her feathers are fluffed out. Poop production is way down but then she's not eating. She can stand but prefers not to. Today I've been giving her 3ccs of electrolyte solution about every two hours. I have noticed her pupils getting bigger and smaller but am not certain if that is a symptom of illness or just a sign of stress. Does this sound like Marek's? If so, is she likely to pull through or would I do better to cull her? I only have a small flock of six other pullets so she would be missed. Is there something else I could be doing for her short of taking her to a vet?