Coccidiosis in peafowl is generally just found in birds 3 to 12 weeks old. I am told it is not contagious.
How ever if one starts to show symptoms then you will soon see the same in other birds in that hatch. The most prominent symptom is the bird walks slow with it’s neck hunched into it’s shoulders and is passing a black, watery stool
To mitigate, treat with a coccidiostat that can be added to the water. I do not use any coccidiostat that need to be added to the food if birds are already showing symptoms. The reason for this is that if a bird is unwell it will often go off it’s food and even stop eating all together so not eat the coccidiostat treatment. I always use a coccidiostat that can be added to the water. Even ill birds seem to keep drinking. It is how ever very important you do not overdose the treatment if adding it to drinking water as this can taint the water and stop the birds from drinking their dose rate. We use coccidiostat in the water has a preventative medication in all our peafowl. Starting at 3 weeks then 6 weeks and again at 12 weeks. I have treated peafowl at 16 weeks if I have seen symptoms in the birds, but this has only been the case if they where not treated at a younger age.
I have found that starting to worm your birds at a young age is a great help in the prevention of coccidiosis. Worming your birds is not a cure. I would have to say it is more good animal management. Check my worming peafowl page for more details.