21 CFR § 558.633 - Tylvalosin.

---
identifier: "/us/cfr/t21/s558.633"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 558.633 - Tylvalosin."
title_number: 21
title_name: "Food and Drugs"
section_number: "558.633"
section_name: "Tylvalosin."
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"
---


# 558.633 Tylvalosin.

(a) *Specifications.* Type A medicated articles containing 77.12 grams tylvalosin per pound as tylvalosin tartrate.

(b) *Sponsor.* See No. 066916 in § 510.600(c) of this chapter.

(c) *Related tolerances.* See § 556.748 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) VFDs for tylvalosin shall not be refilled.

(3) Crumbled Type C medicated feeds must bear an expiration date of 7 days after the date of manufacture.

(e) *Conditions of use.*

| Tylvalosin ingrams/ton | Indications for use | Limitations | Sponsor |
| --- | --- | --- | --- |
| (i) 38.6 | Swine: For the control of porcine proliferative enteropathy (PPE) associated with  infection in groups of swine in buildings experiencing an outbreak of PPE. | Feed continuously as the sole ration for 14 consecutive days. | 066916 |
| (ii) [Reserved] |  |  |  |

[81 FR 36790, June 8, 2016, as amended at 81 FR 67153, Sept. 30, 2016; 84 FR 12504, Apr. 2, 2019; 87 FR 17948, Mar. 29, 2022; 87 FR 58968, Sept. 29, 2022]