Sorry for your loss.We put the little pullet down today. She had been growing steadily weaker over the past 72 hours. Today she was finding it hard to impossible to even stand up once she had laid down. I was working out in the run and saw her manage to get upright and inside where she lay down in a corner. Some of her siblings joined her then one by one left. She stayed in her corner and didn't try to join them. My remaining mature OEGB hen, the one who ISN'T broody, went inside and began to attack her. I intervened and when I picked her up I noticed that her crop was empty and she just didn't seem to have any fight left in her I can't blame Little Dove. She was telling me the sick one was near the end. Little Blondie was alert but almost fell asleep in my arms. We set and 'talked' for awhile. Then DH came outside and we set her little soul free.
No doubt that it was Marek's. Her symptoms were classic. She had just turned 7 weeks today.