I have lost two Marans chicks out of the three that I had, I emailed the person I got them from and she said she has lost three chicks to the same symptoms in the last month. My problem is my chicks were brooded by her Marans chicken so they were exposed to her Marans from the start. She said that she has not lost a Marans but lost a couple chickens in pens near them. My dilemma is this I still have one of the marans I got from her, it is in with 7 barnyard mix chicks that it has been in with since they were about 3 weeks old, they are 8 weeks old now. What do I do? do I wait to see if they show sypmtoms or cull them to make sure my whole flock doesnt get it? what are the odds that if it was Mareks that all of them have it?