#### § 558.575 Sulfadimethoxine and ormetoprim.

(a) *Specifications.* Type A medicated articles containing either:

(1) 25 percent sulfadimethoxine and 15 percent ormetoprim; or

(2) 25 percent sulfadimethoxine and 5 percent ormetoprim.

(b) *Sponsors.* See sponsors in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)) as follows:

(1) No. 054771 for use of the product described in paragraph (a)(1) as in [paragraphs (e)(1)](/on/2024-09-17/title-21/section-558.575#p-558.575(e)(1)), [(e)(2)(i)](/on/2024-09-17/title-21/section-558.575#p-558.575(e)(2)(i)), and [(e)(3)(i)](/on/2024-09-17/title-21/section-558.575#p-558.575(e)(3)(i)) through [(iii)](/on/2024-09-17/title-21/section-558.575#p-558.575(e)(3)(iii)) of this section.

(2) No. 015331 for use of the product described in paragraph (a)(2) as in [paragraphs (e)(3)(iv)](/on/2024-09-17/title-21/section-558.575#p-558.575(e)(3)(iv)) and [(v)](/on/2024-09-17/title-21/section-558.575#p-558.575(e)(3)(v)) of this section.

(c) *Related tolerances.* See [§§ 556.490](/on/2024-09-17/title-21/section-556.490) and [556.640 of this chapter](/on/2024-09-17/title-21/section-556.640).

(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](/on/2024-09-17/title-21/section-558.6) for additional requirements.

(2) The expiration date of VFDs for sulfadimethoxine and ormetoprim medicated feeds must not exceed 6 months from the date of issuance. VFDs for sulfadimethoxine and ormetoprim shall not be refilled.

(e) *Conditions of use.* It is used in animal feeds as follows:

(1) *Chickens* —

| Sulfadimethoxine and ormetoprim grams/ton | Indications for use | Limitations | Sponsors |
| --- | --- | --- | --- |
| (i) Sulfadimethoxine, 113.5; ormetoprim, 68.1. | Broiler chickens: As an aid in the prevention of coccidiosis caused by all *Eimeria* species known to be pathogenic to chickens, namely, *E. tenella, E. necatrix, E. acervulina, E. brunetti, E. mivati,* and *E. maxima,* and bacterial infections due to *Heterakis gallinarum* (infectious coryza), *Escherichia coli* (colibacillosis) and *Pasteurella multocida* (fowl cholera). | Feed as sole ration. Withdraw 5 days before slaughter. | 054771 |
| (ii) Sulfadimethoxine, 113.5; ormetoprim, 68.1. | Replacement chickens: As an aid in the prevention of coccidiosis caused by all *Eimeria* species known to be pathogenic to chickens, namely, *E. tenella, E. necatrix, E. acervulina, E. brunetti, E. mivati,* and *E. maxima,* and bacterial infections due to *Heterakis gallinarum* (infectious coryza), *Escherichia coli* (colibacillosis) and *Pasteurella multocida* (fowl cholera). | Feed as sole ration. Do not feed to chickens over 16 weeks (112 days) of age. Withdraw 5 days before slaughter. | 054771 |

(2) *Turkeys* —

| Sulfadimethoxine and ormetoprim grams/ton | Indications for use | Limitations | Sponsors |
| --- | --- | --- | --- |
| (i) Sulfadimethoxine, 56.75; ormetoprim, 34.05. | Turkeys: As an aid in the prevention of coccidiosis caused by all *Eimeria* species known to be pathogenic to turkeys, namely, *E. adenoeides, E. gallopavonis,* and *E. meleagrimitis* and bacterial infection due to *Pasteurella multocida* (fowl cholera). | Do not feed to turkeys producing eggs for food. Withdraw 5 days before slaughter. | 054771 |
| (ii) [Reserved] | | | |

(3) *Minor species* —

| Sulfadimethoxine and ormetoprim amount | Indications for use | Limitations | Sponsors |
| --- | --- | --- | --- |
| (i) Sulfadimethoxine, 227; ormetoprim, 136.2 grams/ton of feed. | Ducks, including breeding ducks: As an aid in the control of bacterial infections due to *Pasteurella multocida* (fowl cholera). | Feed as sole ration for 7 days. Medication should be started at the first signs of infection. Do not feed to ducks producing eggs for food. Withdraw 5 days before slaughter. | 054771 |
| (ii) Sulfadimethoxine, 454; ormetoprim, 272.4 grams/ton of feed. | Ducks: As an aid in the control of bacterial infections due to *Escherichia coli, Riemerella anatipestifer,* and severe challenge of *Pasteurella multocida* (fowl cholera). | Feed as a sole ration for 7 days. Medication should be started at the first signs of infection. Not for breeding ducks. Do not feed to ducks producing eggs for food. Withdraw 5 days before slaughter. | |
| (iii) Sulfadimethoxine, 113.5; ormetoprim, 68.1 grams/ton of feed. | Chukar partridges: For prevention of coccidiosis caused by *Eimeria kofoidi* and *E. legionensis.* | Feed continuously to young birds up to 8 weeks of age as sole ration. | 054771 |
| (iv) 630 to 3780 g/ton sulfadimethoxine and 126 to 756 g/ton ormetoprim to provide 50 milligrams (mg) of active ingredients per kilogram of body per day | Salmonids: For the control of furunculosis in salmonids (trout and salmon) caused by *Aeromonas salmonicida* strains susceptible to sulfadimethoxine and ormetoprim combination | Administer for 5 consecutive days. Withdraw 42 days before release as stocker fish or slaughter | 015331 |
| (v) 630 to 3780 g/ton sulfadimethoxine and 126 to 756 g/ton ormetoprim to provide 50 mg of active ingredients per kilogram of body per day | Catfish: For control of enteric septicemia of catfish caused by *Edwardsiella ictaluri* strains susceptible to sulfadimethoxine and ormetoprim combination | Administer for 5 consecutive days. Withdraw 3 days before slaughter or release as stocker fish | 015331 |

[[40 FR 13959](https://www.federalregister.gov/citation/40-FR-13959), Mar. 27, 1975, as amended at [42 FR 13550](https://www.federalregister.gov/citation/42-FR-13550), Mar. 11, 1977; [49 FR 33442](https://www.federalregister.gov/citation/49-FR-33442), Aug. 23, 1984; [49 FR 46371](https://www.federalregister.gov/citation/49-FR-46371), Nov. 26, 1984; [51 FR 7400](https://www.federalregister.gov/citation/51-FR-7400), Mar. 3, 1986; [51 FR 18884](https://www.federalregister.gov/citation/51-FR-18884), May 23, 1986; [52 FR 2686](https://www.federalregister.gov/citation/52-FR-2686), Jan. 26, 1987; [54 FR 1686](https://www.federalregister.gov/citation/54-FR-1686), Jan. 17, 1989; [63 FR 27846](https://www.federalregister.gov/citation/63-FR-27846), May 21, 1998; [64 FR 26672](https://www.federalregister.gov/citation/64-FR-26672), May 17, 1999; [64 FR 43910](https://www.federalregister.gov/citation/64-FR-43910), Aug. 12, 1999; [66 FR 46707](https://www.federalregister.gov/citation/66-FR-46707), Sept. 7, 2001; [70 FR 52292](https://www.federalregister.gov/citation/70-FR-52292), Sept. 2, 2005; [79 FR 10983](https://www.federalregister.gov/citation/79-FR-10983), Feb. 27, 2014; [79 FR 13546](https://www.federalregister.gov/citation/79-FR-13546), Mar. 11, 2014; [81 FR 95013](https://www.federalregister.gov/citation/81-FR-95013), Dec. 27, 2016; [83 FR 13637](https://www.federalregister.gov/citation/83-FR-13637), Mar. 30, 2018; [84 FR 12502](https://www.federalregister.gov/citation/84-FR-12502), Apr. 2, 2019; [86 FR 14827](https://www.federalregister.gov/citation/86-FR-14827), Mar. 19, 2021; [87 FR 76424](https://www.federalregister.gov/citation/87-FR-76424), Dec. 14, 2022]