---
kind: "section"
citation: "21 C.F.R. § 520.1664"
title: "21"
number: "520.1664"
heading: "Oxytetracycline and carbomycin."
url: "https://uscodex.org/cfr/21/520.1664"
---

# §520.1664. Oxytetracycline and carbomycin.

- (a) **Specifications.**
  - (1) **Oxytetracycline—** The antibiotic substance produced by growth of Streptomyces rimosus or the same antibiotic substance produced by any other means.
  - (2) **Carbomycin—** The antibiotic substance produced by growth of Streptomyces halstedii or the same antibiotic substance produced by any other means.
- (b) **Sponsor.** See No. 054771 in [§ 510.600(c)](/cfr/21/510.600.md?p=c) of this chapter.
- (c) **Special considerations.** The quantities of oxytetracycline in [paragraph (e)](#e) of this section refer to the activity of oxytetracycline hydrochloride and the quantities of carbomycin listed refer to the activity of an appropriate standard.
- (d) **Related tolerances.** See §§ [556.110](/cfr/21/556.110.md) and [556.500](/cfr/21/556.500.md) of this chapter.
- (e) **Conditions of use.** It is used as oxytetracycline hydrochloride plus carbomycin base in drinking water of chickens as follows:
  - (1) **Amount.** Administer 1.0 gram of oxytetracycline and 1.0 gram carbomycin per gallon for not more than 5 days.
  - (2) **Indications for use.** As an aid in the prevention and treatment of complicated chronic respiratory disease (air-sac infection) caused by Mycoplasma gallisepticum and secondary bacterial organisms associated with chronic respiratory disease such as E. coli.
  - (3) **Limitations.** Not for use in chickens producing eggs for human consumption. Withdraw 24 hours before slaughter. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

## Notes

### Amendments

[40 FR 13838, Mar. 27, 1975, as amended at 78 FR 28825, May 20, 2014; 81 FR 94989, Dec. 27, 2016. Redesignated at 88 FR 55563, Aug. 16, 2023]

### Authority

Authority: 21 U.S.C. 360b.

### Source

Source: 40 FR 13838, Mar. 27, 1975, unless otherwise noted.

### Amendments

[40 FR 13838, Mar. 27, 1975, as amended at 78 FR 28825, May 20, 2014; 81 FR 94989, Dec. 27, 2016. Redesignated at 88 FR 55563, Aug. 16, 2023]