21 CFR § 522.234 - Butamisole.

---
identifier: "/us/cfr/t21/s522.234"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 522.234 - Butamisole."
title_number: 21
title_name: "Food and Drugs"
section_number: "522.234"
section_name: "Butamisole."
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: "522"
part_name: "IMPLANTATION OR INJECTABLE 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 13858, Mar. 27, 1975, unless otherwise noted."
cfr_part: "522"
---


# 522.234 Butamisole.

(a) *Specifications.* Each milliliter of solution contains 11 milligrams (mg) butamisole hydrochloride.

(b) *Sponsors.* See Nos. 054771 and 058198 in § 510.600(c) of this chapter.

(c) *Conditions of use in dogs*—(1) *Amount.* Administer 0.1 mg per pound of body weight by subcutaneous injection. In problem cases, retreatment for whipworms may be necessary in approximately 3 months. For hookworms, a second injection should be given 21 days after the initial treatment.

(2) *Indications for use.* For the treatment of infections with whipworms (*Trichuris vulpis*), and the hookworm (*Ancylostoma caninum*).

(3) *Limitations.* Federal law restricts this drug to use by or on the order of a licensed veterinarian.

[79 FR 16184, Mar. 25, 2014, as amended at 86 FR 14819, Mar. 19, 2021]