WOW. How HORRIBLE for you. I can't imagine having to cull the entire flock at once.
I know you are supposed to keep new animals separate from the rest....but for HOW LONG? And how can you be SURE that you are doing everything right & when it's safe??
The same thing happened with us & a dog we "rescued"...it seemed fine, then all our original dogs & that one, lost their minds...distemper. It was gruesome. VACCINATE YOUR DOGS. lesson learned....
But how do you know it's safe to introduce a new bird to the flock? If it's something you can carry on your clothing, then how can you be safe making your rounds tending to the animals?? You would have to bathe & change clothing between flocks/birds just to feed & water...
All of my flock came from two Old English Games, that were given to me. Just the two. I'm on my third year of having them, and if I count this year's hatch, I now have 22 birds (16 being this year's hatch) I would like to have some different breeds, but I am scared out of my head to get a new one because things like this can & do happen.