21 CFR § 558.630 - Tylosin and sulfamethazine.

---
identifier: "/us/cfr/t21/s558.630"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 558.630 - Tylosin and sulfamethazine."
title_number: 21
title_name: "Food and Drugs"
section_number: "558.630"
section_name: "Tylosin and sulfamethazine."
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: "558"
part_name: "NEW ANIMAL DRUGS FOR USE IN ANIMAL FEEDS"
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. 354, 360b, 360ccc, 360ccc-1, 371."
regulatory_source: "40 FR 13959, Mar. 27, 1975, unless otherwise noted."
cfr_part: "558"
---


# 558.630 Tylosin and sulfamethazine.

(a) *Specifications.* Type A medicated articles containing equal amounts of tylosin phosphate and sulfamethazine, available in concentrations of 5, 10, 20, or 40 grams each, per pound.

(b) *Sponsors.* See sponsor numbers in § 510.600(c) of this chapter.

(1) No. 058198 for use as in paragraph (e)(1) of this section.

(2) No. 066104: 10 or 40 grams per pound each for use as in paragraph (e)(2) of this section.

(c) *Related tolerances.* See §§ 556.670 and 556.746 of this chapter.

(d) *Special considerations.* (1) Federal law restricts medicated feed containing this veterinary feed directive (VFD) drug to use by or on the order of a licensed veterinarian. See § 558.6 for additional requirements.

(2) The expiration date of VFDs for tylosin and sulfamethazine medicated feeds must not exceed 6 months from the date of issuance. VFDs for tylosin and sulfamethazine shall not be refilled.

(3) Labeling shall bear the statement: “Do not use in medicated feeds containing in excess of 2% bentonite.”

(e) *Conditions of use.* It is used in feed for swine as follows:

| Tylosin phosphate and sulfamethazinein grams/ton | Combination in grams/ton | Indications for use | Limitations | Sponsors |
| --- | --- | --- | --- | --- |
| (1) 100 each |  | For reduction in the severity of effects of atrophic rhinitis; lowering the incidence and severity of  rhinitis; prevention of swine dysentery associated with  control of swine pneumonias caused by bacterial pathogens ( and/or ); reducing the incidence of cervical lymphadenitis (jowl abscesses) caused by Group E  Only the sulfamethazine portion of this combination is active in controlling jowl abscesses | Withdraw 15 days before swine are slaughtered | 058198 |
| (2) 100 each |  | For reduction in the severity of effects of atrophic rhinitis; lowering the incidence and severity of  rhinitis; prevention of swine dysentery associated with  and control of swine pneumonias caused by bacterial pathogens ( and/or ) | Withdraw 15 days before swine are slaughtered | 066104 |

[81 FR 95021, Dec. 27, 2016, as amended at 84 FR 33002, July 11, 2019; 91 FR 5303, Feb. 6, 2026]