5 are dead all of a sudden

[deineria]

4 of our started - 8 week old - W/BW Ameraucana chicks and 1 of our BCMs were dead this morning -
nothing obviously wrong. Doing well yesterday. . .
on medicated feed, just did a cocci treatment last week . . .
NPIP certified 3 weeks ago. . .

Any ideas?

 

[Anianna]

I have been told that several states will test dead birds from NPIP certified facilities for free to find out what they died from.