I doubled the bedding and will address the area they’re sleeping daily. There’s a ten or more foot overhang on the roof but I’m wondering if rain with a cold front made it in the coop. I’ll keep a close watch.Only separate if you want to give her more attention or feed her the undiluted Corid. She may be more comfortable with her flock. If she is acting sick, go ahead and separate. The main thing with prevention is to keep the coop as dry and clean as possible. You cannot really disinfect a coop or wven the roosts. Dry is good. Stirring the bedding and adding new pine shavings often are good moves. Good air circulation can help with keeping it dry. Clean and wash waterers daily and raise feeders and waterers to shoulder height to lessen the possibility of droppings getting into them.
Please nitpick!!! Thank you.You could easily have brought the protozoa or its oocysts in on your shoes. It can be brought in on feeders, water founts and many other pieces of equipment.
Your adult flock has long ago developed resistance. The reason chicks are so vulnerable is that the first time they've been exposed, they haven't had an opportunity to develop resistance.
I know some people will put a piece of garden soil in their brooders to give slight exposure. That may be of some help. There are 7 species of coccidia (eimeria) that affect chickens, 5 that affect turkeys and one species in ducks. Not all species are in every environment. Should your or anyone's birds that have resistance to the species on a property be sold and move to a property with a different species, that is when adults can be affected by an outbreak of coccidiosis. As long as they are responding to the Corid, you are probably out of the woods and can continue to allow them to forage.
Not to nitpick but another point I'd like to clarify is that the pathogen causing coccidiosis is the protozoa coccidia, not cocci. Cocci is any spherical shaped microorganism - usually bacteria.