When to give new chickens corid??

[2jsbabyfarm]

Ready to introduce a few new hens to our flock (yes they have been through proper quarantine=)) our established flock has had and been treated for cocci in the past so I'm just wondering when I should start corid for the new hens? After they show symptoms? Right away?

 

[Wyandottes7]

I wouldn't give Corid until you see any symptoms of Coccidiosis. However, if you notice something is wrong and think that its Coccidiosis, give it immediately. Coccidiosis can kill quickly, so prompt treatment can be important.