21 CFR § 520.823 - Erythromycin.

---
identifier: "/us/cfr/t21/s520.823"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 520.823 - Erythromycin."
title_number: 21
title_name: "Food and Drugs"
section_number: "520.823"
section_name: "Erythromycin."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "E"
subchapter_name: "ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS"
part_number: "520"
part_name: "ORAL DOSAGE FORM NEW ANIMAL DRUGS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "21 U.S.C. 360b."
regulatory_source: "40 FR 13838, Mar. 27, 1975, unless otherwise noted."
cfr_part: "520"
---


# 520.823 Erythromycin.

(a) *Specifications.* Each gram of powder contains erythromycin phosphate equivalent to 0.89 gram of erythromycin master standard.

(b) *Sponsor.* See No. 061133 in § 510.600(c) of this chapter.

(c) *Related tolerances.* See § 556.230 of this chapter.

(d) *Conditions of use.* It is used in drinking water as follows:

(1) *Broiler and replacement chickens*—(i) *Amount.* Administer 0.500 gram per gallon for 5 days.

(ii) *Indications for use.* As an aid in the control of chronic respiratory disease due to *Mycoplasma gallisepticum* susceptible to erythromycin.

(iii) *Limitations.* Do not use in replacement pullets over 16 weeks of age. Do not use in chickens producing eggs for human consumption. Withdraw 1 day before slaughter. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

(2) *Replacement chickens and chicken breeders*—(i) *Amount.* Administer 0.500 gram per gallon for 7 days.

(ii) *Indications for use.* As an aid in the control of infectious coryza due to *Haemophilus gallinarum* susceptible to erythromycin.

(iii) *Limitations.* Do not use in replacement pullets over 16 weeks of age. Do not use in chickens producing eggs for human consumption. Withdraw 1 day before slaughter. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

(3) *Growing turkeys*—(i) *Amount.* Administer 0.500 gram per gallon for 7 days.

(ii) *Indications for use.* As an aid in the control of blue comb (nonspecific infectious enteritis) caused by organisms susceptible to erythromycin.

(iii) *Limitations.* Do not use in turkeys producing eggs for human consumption. Withdraw 1 day before slaughter. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

[40 FR 13838, Mar. 27, 1975, as amended at 45 FR 56798, Aug. 26, 1980; 66 FR 14073, Mar. 9, 2001; 68 FR 4914, Jan. 31, 2003; 79 FR 28821, May 20, 2014; 81 FR 17607, Mar. 30, 2016; 81 FR 94989, Dec. 27, 2016; 84 FR 8972, Mar. 13, 2019]