#### § 558.140 Chlortetracycline and sulfamethazine.

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

(1) 35 grams (g) per pound (/lb) each, chlortetracycline and sulfamethazine.

(2) 40 g/lb each, chlortetracycline and sulfamethazine.

(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 product described in paragraph (a)(1) as in [paragraph (e)(1)](/on/2024-09-17/title-21/section-558.140#p-558.140(e)(1)) of this section.

(2) No. 069254 for use of product described in paragraph (a)(1) as in [paragraph (e)(1)(i)](/on/2024-09-17/title-21/section-558.140#p-558.140(e)(1)(i)) of this section.

(3) Nos. 054771 and 069254 for use of product described in paragraph (a)(2) as in [paragraph (e)(2)](/on/2024-09-17/title-21/section-558.140#p-558.140(e)(2)) of this section.

(c) *Related tolerances.* See [§§ 556.150](/on/2024-09-17/title-21/section-556.150) and [556.670 of this chapter](/on/2024-09-17/title-21/section-556.670).

(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 chlortetracycline and sulfamethazine medicated feeds must not exceed 6 months from the date of issuance. VFDs for chlortetracycline and sulfamethazine shall not be refilled.

(e) *Conditions of use* —

(1) *Cattle* —

| Chlortetracycline and sulfamethazine amount each | Combination in grams/ton | Indications for use | Limitations | Sponsors |
| --- | --- | --- | --- | --- |
| (i) To provide 350 milligrams per head per day | | Beef cattle: As an aid in the maintenance of weight gains in the presence of respiratory disease such as shipping fever. | Feed for 28 days. Withdraw 7 days prior to slaughter. A withdrawal period has not been established for this product in pre-ruminating calves. Do not use in calves to be processed for veal. | 054771 069254 |
| (ii) 35 to 105 g/ton, each | Lasalocid, 10 to 30 | Beef steers and heifers fed in confinement for slaughter: As an aid in the maintenance of weight gains in the presence of respiratory disease such as shipping fever, and for improved feed efficiency. | Feed continuously for 28 days to provide 350 mg chlortetracycline, 350 mg sulfamethazine, and 100 to 300 mg lasalocid per head per day. Do not allow horses or other equines access to Type C feeds containing lasalocid as ingestion may be fatal. Safety of lasalocid for use in unapproved species has not been established. Withdraw 7 days prior to slaughter. A withdrawal period has not been established for this product in pre-ruminating calves. Do not use in calves to be processed for veal. Lasalocid as provided by No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)). | 054771 |
| (iii) 35 to 42.2 g/ton, each | Lasalocid, 25 to 30 | Beef steers and heifers fed in confinement for slaughter: As an aid in the maintenance of weight gains in the presence of respiratory disease such as shipping fever, and for improved feed efficiency and increased rate of weight gain. | Feed continuously for 28 days to provide 350 mg chlortetracycline, 350 mg sulfamethazine, and 250 to 300 mg lasalocid per head per day. Do not allow horses or other equines access to Type C feeds containing lasalocid as ingestion may be fatal. Safety of lasalocid for use in unapproved species has not been established. Withdraw 7 days prior to slaughter. A withdrawal period has not been established for this product in pre-ruminating calves. Do not use in calves to be processed for veal. Lasalocid as provided by No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)). | 054771 |
| (iv) 35 to 700 g/ton, each | Lasalocid, 30 to 181.8 | Beef cattle up to 800 lb: As an aid in the maintenance of weight gains in the presence of respiratory disease such as shipping fever, and for control of coccidiosis caused by *Eimeria bovis* and *E. zuernii*. | Hand feed continuously for 28 days to provide 350 mg chlortetracycline, 350 mg sulfamethazine, and 1 mg lasalocid per 2.2 lb body weight per day up to a maximum of 360 mg lasalocid per head per day. Do not allow horses or other equines access to Type C feeds containing lasalocid as ingestion may be fatal. Safety of lasalocid for use in unapproved species has not been established. Withdraw 7 days prior to slaughter. A withdrawal period has not been established for this product in pre-ruminating calves. Do not use in calves to be processed for veal. Lasalocid as provided by No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)). | 054771 |

(2) *Swine* —

| Chlortetracycline and sulfamethazine amount | Indications for use | Limitations | Sponsors |
| --- | --- | --- | --- |
| (i) 100 g/ton of feed each, chlortetracycline and sulfamethazine | Swine: For reduction of the incidence of cervical abscesses; treatment of bacterial swine enteritis (salmonellosis or necrotic enteritis caused by *Salmonella choleraesuis* and vibrionic dysentery); prevention of these diseases during times of stress; and maintenance of weight gains in the presence of atrophic rhinitis | Feed as the sole ration. Withdraw 15 days prior to slaughter | 054771 069254 |
| (ii) [Reserved] | | | |

[[79 FR 37622](https://www.federalregister.gov/citation/79-FR-37622), July 2, 2014, as amended at [80 FR 13231](https://www.federalregister.gov/citation/80-FR-13231), Mar. 13, 2015; [81 FR 63054](https://www.federalregister.gov/citation/81-FR-63054), Sept. 14, 2016; [81 FR 95004](https://www.federalregister.gov/citation/81-FR-95004), Dec. 27, 2016; [82 FR 21691](https://www.federalregister.gov/citation/82-FR-21691), May 10, 2017; [84 FR 12495](https://www.federalregister.gov/citation/84-FR-12495), Apr. 2, 2019; [86 FR 13189](https://www.federalregister.gov/citation/86-FR-13189), Mar. 8, 2021; [86 FR 14822](https://www.federalregister.gov/citation/86-FR-14822), Mar. 19, 2021]