I have been watching these postings for a while now and finally decided to post. Please bear with me, I've never posted before.
I, too, have sick chicks from McMurray. They will be 3 weeks on Saturday and started getting sick at about 1-1/2 weeks. The symptoms are the same. I would have to agree that it sounds like AE.
Out of 13, I have 5 in the "sick" brooder and have lost one...the other 7 are currently healthy. I've got one sick brahma, 2 wyandottes, and 2 speckled sussex. All my marans are fine. Two of the chicks seem to be doing much better and are walking fine, but I am still keeping them with the sick bunch.
MY order was split with a friend (we divided the order immediately). At first, it was just me with the problems, so I assumed it was something I did. Then, yesterday, 3 of hers came down with it. We called McMurray and they were very nice about it, but had no idea what could be wrong. We are receiving replacements for the chicks on Monday. I ordered from McMurray last year and got perfectly healthy chicks...didn't lose even one. But...in this case, it does seem to be something that happened at the hatchery.
I'm very worried about the new chicks. Is keeping them in a separate brooder enough? Should I keep them in different rooms too?
Thank you to everyone taking their chicks in. I'll be anxiously awaiting the outcome.