It's hard to get rid of coccidia completely. All birds naturally have a little coccidia living in their bowls, and it normally does not cause them much problem. It's when they become stressed and infested. Too much coccidia of course causes coccidiosis. Those little coccidia burrow into the lining of the bowl walls, lay eggs, which burst out and make little pin holes in the wall. So as you can probably tell, too much damage to a bird's insides is deadly!
