Your feed store will have what you need. Corid is a brand name in the States, Amprolium is generic name. Should have two dosages listed, one for standard, routine treatment, another for 'outbreak'; I'd give them the higher dosage just for certainty.
In no way will treatment hurt your birds or cause you to discard any eggs laid while being treated; it's not an antibiotic.
In no way will treatment hurt your birds or cause you to discard any eggs laid while being treated; it's not an antibiotic.