And that's the sad truth of broody hatching. It can be such a crap shoot some years, even with very faithful, experienced hens...a disastrous year. (This was my year for it too...a skunk got into my hatches wrecking havoc on my first sets).
Hopefully next clutches go better. Generally they do...
It's highly doubtful that would be coccidiosis. The life cycle of the coccidia are such that, even with the speediest of exposure, growth, infestation, manifestation, you are looking at least at almost 4 weeks for a very early development of coccidiosis as the chicken has to eat the oocyst...
I agree with Casportpony and Eggcessive, the swollen eyes are not from coccidiosis. That is another matter....and starting a thread in emergencies and illnesses would be good.
The coccidiosis likely lowered their immune system so that another opportunistic infection occurred.
Coryza, MG, and...
I have sadly had coccidiosis several times in my flock. Once very mild. Once fairly significant.
The mild I treated with extended amprolium based medicated feed. The significant infection I treated with Sulmet, which worked very well. After that, I fed medicated feed until point of lay.
Who...