Gardeningmama, amprolium (medicated chick starter) is just a coccidiostat, not a coccidiocide. If you have a particularly strong strain of coccidia, or if your birds get a really high dose of the parasite, or if conditions are wet and humid and damp and muggy and all of those synonyms which coccidiosis loves to flourish in, you can still have birds come down with it.
That is when you administer a sulfa drug according to veterinarian or label instructions.
That is when you administer a sulfa drug according to veterinarian or label instructions.