21 CFR § 520.2220f - Sulfadimethoxine and ormetoprim tablet.

---
identifier: "/us/cfr/t21/s520.2220f"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 520.2220f - Sulfadimethoxine and ormetoprim tablet."
title_number: 21
title_name: "Food and Drugs"
section_number: "520.2220f"
section_name: "Sulfadimethoxine and ormetoprim tablet."
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"
---


# 520.2220f Sulfadimethoxine and ormetoprim tablet.

(a) *Specifications.* Each tablet contains 120 milligrams (mg) (100 mg sulfadimethoxine and 20 mg ormetoprim), 240 mg (200 mg sulfadimethoxine and 40 mg ormetoprim), 600 mg (500 mg sulfadimethoxine and 100 mg ormetoprim), or 1200 mg (1000 mg sulfadimethoxine and 200 mg ormetoprim).

(b) *Sponsor.* See No. 054771 in § 510.600(c) of this chapter.

(c) *Conditions of use in dogs*—(1) *Amount.* On the first day of treatment, administer 25 mg per pound (55 mg per kilogram) of body weight. Then follow with a daily dosage of 12.5 mg per pound (27.5 mg per kilogram) of body weight. Do not exceed a total of 21 consecutive days.

(2) *Indications of use.* Treatment of skin and soft tissue infections (wounds and abscesses) in dogs caused by strains of *Staphylococcus aureus* and *Escherichia coli* and urinary tract infections caused by *E. coli, Staphylococcus* spp., and *Proteus mirabilus* susceptible to ormetoprim-potentiated sulfadimethoxine.

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

[79 FR 28830, May 20, 2014]