Parental kill urge is an understatement with dog bites. And I am sorry for the poster that's BO's are missing. I'd be furious as well as worried!
I have 2 Buff Cochins & 2 Australs (same age) in the brooder doing the clicking. Only 1 of the Australs isn't doing it. However, they are still growing, eating, drinking, normal poop etc. no discharge or crusties. Whatver it is, seems mild. I was going to wait to try Tylan until they've had the full course of Duraycin so j don't cause them antibiotic resistence.
At this point I feel I am doing all I can & it's a waitig game. Frustrating for sure, but I knew it could happen. Esp buying at Feed Stores