I'm wondering if there are any illnesses that meet *all* of the following criteria (not some): Passable from mother hen to her chicks, and then those chicks to other chicks. The reason I ask is because I'm wondering if I can put my newly hatched chick in with the healthy 4 day olds or if I should keep her quarantined for some reason. She hatched here in our house. We also have two 1 month old NJs that are very healthy as well but are in a separate brooder (same room in the house). There are 2 EE, 2 GLB and 1 GB living together in harmony and good health in the brooder the new chick would be placed in - I don't want to mess up anyone's health. Thanks in advance!