---
kind: "section"
citation: "21 C.F.R. § 520.905c"
title: "21"
number: "520.905c"
heading: "Fenbendazole paste."
url: "https://uscodex.org/cfr/21/520.905c"
---

# §520.905c. Fenbendazole paste.

- (a) **Specifications.** Each gram of paste contains 100 milligrams (mg) fenbendazole (10 percent).
- (b) **Sponsor.** See No. 000061 in [§ 510.600(c)](/cfr/21/510.600.md?p=c) of this chapter.
- (c) **Related tolerances.** See [§ 556.275](/cfr/21/556.275.md) of this chapter.
- (d) **Special considerations.** See [§ 500.25](/cfr/21/500.25.md) of this chapter.
- (e) **Conditions of use—**
  - (1) **Horses—**
    - (i) **Indications for use and amounts.**
      - (A) **For the treatment and control of large strongyles (<I>Strongylus edentatus, S.** equinus, S. vulgaris), small strongyles, and pinworms (Oxyuris equi). For large strongyles, small strongyles, and pinworms, the recommended dose is 5 mg/kg (2.3 mg/lb).
      - (B) **For treatment and control of ascarids (<I>Parascaris equorum</I>).** For ascarids, the recommended dose is 10 mg/kg (4.6 mg/lb).
      - (C) For treatment and control of hypobiotic (encysted early third-stage), late third-stage, and fourth-stage cyathostome larvae, as well as fourth-stage Strongylus vulgaris larvae, the recommended dose is 10 mg/kg (4.6 mg/lb) daily for 5 consecutive days.
      - (D) **For the control of arteritis caused by fourth-stage larvae of <I>Strongylus vulgaris</I> in horses.**
      - (E) Fenbendazole paste 10 percent may be used concomitantly with approved forms of trichlorfon for the indications provided in [paragraph (e)(1)(i)(A)](#e-1-i-A) of this section and for treating infections of stomach bots as provided in [§ 520.2520](/cfr/21/520.2520.md).
    - (ii) **Limitations.** Do not use in horses intended for human consumption.
  - (2) **Beef and dairy cattle—**
    - (i) **Amount.** Administer orally 2.3 mg/lb (5 mg/kg) body weight.
    - (ii) **Indications for use.** For the treatment and control of: Lungworms: Adult (Dictyocaulus viviparus); Stomach worms: Adult brown stomach worms (Ostertagia ostertagi), adult and fourth-stage larvae barberpole worms (Haemonchus contortus), fourth-stage larvae barberpole worms (H. placei), and adult and fourth-stage larvae small stomach worms (Trichostrongylus axei); Intestinal worms (adult and fourth-stage larvae): Hookworms (Bunostomum phlebotomum), thread-necked intestinal worms (Nematodirus helvetianus), small intestinal worms (Cooperia punctata and C. oncophora), bankrupt worms (Trichostrongylus colubriformis), and nodular worms (Oesophagostomum radiatum).
    - (iii) **Limitations.** Milk taken during treatment and for 96 hours after the last treatment must not be used for human consumption. Cattle must not be slaughtered for human consumption within 8 days following last treatment with this drug product. Not for use in beef calves less than 2 months of age, dairy calves, and veal calves. A withdrawal period has not been established for this product in preruminating calves.

## Notes

### Amendments

[72 FR 24185, May 2, 2007, as amended at 74 FR 61516, Nov. 25, 2009; 76 FR 17337, Mar. 29, 2011; 86 FR 57996, Oct. 20, 2021; 87 FR 10968, Feb. 28, 2022]

### Authority

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

### Source

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

### Amendments

[72 FR 24185, May 2, 2007, as amended at 74 FR 61516, Nov. 25, 2009; 76 FR 17337, Mar. 29, 2011; 86 FR 57996, Oct. 20, 2021; 87 FR 10968, Feb. 28, 2022]