Nystatin (Mycostatin) is an antifungal drug used to treat candidiasis (yeast infection, aka "sour crop"). The medication must come in direct contact with the organism to be effective, and thus must be administered orally and used to treat oral or gastrointestinal candidiasis. Some isolates of Candida are becoming resistant to nystatin, so it may be used as a carrier for fluconazole.
Typical Dosage: 1 ml/300 g given gavage orally or added to feed, twice a day for 7 days.
Withdrawal Period: In the United States, nystatin is approved for use in laying hens producing eggs intended for human consumption when its given in accordance with each product manufacturer's label directions; where it has a 0-day egg withdrawal period.