21 CFR § 520.905d - Fenbendazole powder.

---
identifier: "/us/cfr/t21/s520.905d"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 520.905d - Fenbendazole powder."
title_number: 21
title_name: "Food and Drugs"
section_number: "520.905d"
section_name: "Fenbendazole powder."
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"
---


# 520.905d Fenbendazole powder.

(a) *Specifications.* Each 2-ounce packet contains 2.27 grams (4 percent) fenbendazole.

(b) *Sponsor.* See No. 000061 in § 510.600(c) of this chapter.

(c) *Related tolerances.* See § 556.275 of this chapter.

(d) *Conditions of use.* It is administered to swine as follows:

(1) *Amount.* 3 milligrams fenbendazole per kilogram body weight per day (1.36 milligrams per pound per day).

(2) *Indications for use.* For removal and control of large roundworms (*Ascaris suum*); lungworms (*Metastrongylus apri*); nodular worms (*Oesophagostomum dentatum, O. quadrispinulatum*); small stomach worms (*Hyostrongylus rubidus*); whipworms (*Trichuris suis*); and kidneyworms (*Stephanurus dentatus*— mature and immature).

(3) *Limitations.* Thoroughly mix the contents of the packet(s) with swine ration and administer according to label directions. Feed as sole ration for 3 consecutive days. Can be fed to pregnant sows. No prior withdrawal of feed or water is necessary. Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism.

[49 FR 18090, Apr. 27, 1984, as amended at 49 FR 20485, May 15, 1984; 66 FR 47960, Sept. 17, 2001; 70 FR 32489, June 3, 2005; 74 FR 61516, Nov. 25, 2009; 83 FR 48945, Oct. 9, 2018]