§ 522.955 Florfenicol. ( a ) *Specifications.* Each milliliter of solution contains: ( 1 ) 300 milligrams (mg) florfenicol in the inactive vehicles 2-pyrrolidone and triacetin. ( 2 ) 300 mg florfenicol in the inactive vehicles n-methyl-2-pyrrolidone, propylene glycol, and polyethylene glycol. ( 3 ) 300 mg florfenicol in the inactive vehicles 2-pyrrolidone and glycerol formal. ( b ) *Sponsors.* See sponsor numbers in § 510.600(c) of this chapter: ( 1 ) No. 000061 for use of product described in paragraph (a)(1) as in paragraph (d)(1)(i); and ( 2 ) No. 000061 for use of product described in paragraph (a)(2) of this section as in paragraphs (d)(1)(ii) and (d)(2) of this section. ( 3 ) Nos. 058005, 058198, and 069043 for use of product described in paragraph (a)(2) of this section as in paragraph (d)(1)(ii) of this section. ( 4 ) No. 055529 for use of product described in paragraph (a)(3) as in paragraph (d)(1)(ii). ( c ) *Related tolerances.* See §§ 500.1410 and 556.283 of this chapter. ( d ) *Conditions of use* — ( 1 ) *Beef and non-lactating dairy cattle.* (i) 300 mg per milliliter (mL) florfenicol in the inactive vehicles 2-pyrrolidone and triacetin: (A) *Amount.* 40 mg/kilogram (kg) body weight as a single subcutaneous injection. (B) *Indications for use.* For treatment of bovine respiratory disease (BRD) associated with *Mannheimia haemolytica*, *Pasteurella multocida*, *Histophilus somni*, and *Mycoplasma bovis* in beef and non-lactating dairy cattle. (C) *Limitations.* Animals intended for human consumption must not be slaughtered within 44 days of treatment. Do not use in female dairy cattle 20 months of age or older. Use of florfenicol in this class of cattle may cause milk residues. A withdrawal period has not been established in pre-ruminating calves. Do not use in calves to be processed for veal. Federal law restricts this drug to use by or on the order of a licensed veterinarian. ( ii ) 300 mg/mL florfenicol in the inactive vehicles n-methyl-2- pyrrolidone, propylene glycol, and polyethylene glycol, or in 2-pyrrolidone and glycerol formal: ( A ) ( 1 ) *Amount.* 20 mg/kg of body weight as an intramuscular injection. A second dose should be administered 48 hours later. Alternatively, 40 mg/kg of body weight as a single subcutaneous injection may be used. ( 2 ) *Indications for use.* For treatment of BRD associated with *Mannheimia haemolytica, Pasteurella multocida*, and *Histophilus somni.* For treatment of bovine interdigital phlegmon (foot rot, acute interdigital necrobacillosis, infectious pododermatitis) associated with *Fusobacterium necrophorum* and *Bacteroides melaninogenicus.* ( B ) ( 1 ) *Amount.* 40 mg/kg of body weight as a single subcutaneous injection. ( 2 ) *Indications for use.* For control of respiratory disease in cattle at high risk of developing BRD associated with *Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni.* ( C ) *Limitations.* Animals intended for human consumption must not be slaughtered within 28 days of the last intramuscular treatment. Nos. 000061, 058005, 058198, and 069043: Animals intended for human consumption must not be slaughtered within 38 days of subcutaneous treatment. No. 055529: Animals intended for human consumption must not be slaughtered within 33 days of subcutaneous treatment. This product is not approved for use in female dairy cattle 20 months of age or older, including dry dairy cows. Use in these cattle may cause drug residues in milk and/or in calves born to these cows. A withdrawal period has not been established in pre-ruminating calves. Do not use in calves to be processed for veal. Federal law restricts this drug to use by or on the order of a licensed veterinarian. (2) *Swine*. (i) 300 mg/mL florfenicol in the inactive vehicles n-methyl-2-pyrrolidone, propylene glycol, and polyethylene glycol: ( A ) *Amount.* 15 mg/kg of body weight as an intramuscular injection. A second dose should be administered 48 hours later. ( B ) *Indications for use.* For the treatment of swine respiratory disease associated with *Actinobacillus pleuropneumoniae, Pasteurella multocida,* *Salmonella* Choleraesuis, *Streptococcus suis, Bordetella bronchiseptica,* and *Glaesserella (Haemophilus) parasuis* in swine except for nursing piglets and swine of reproductive age intended for breeding. ( C ) *Limitations.* Swine intended for human consumption must not be slaughtered within 11 days of the last intramuscular treatment. Federal law restricts this drug to use by or on the order of a licensed veterinarian. ( ii ) [Reserved] [73 FR 21041, Apr. 18, 2008, as amended at 74 FR 66574, Dec. 16, 2009; 79 FR 18158, Apr. 1, 2014; 79 FR 53136, Sept. 8, 2014; 80 FR 61296, Oct. 13, 2015; 80 FR 76386, Dec. 9, 2015; 86 FR 14819, Mar. 19, 2021; 87 FR 10969, Feb. 28, 2022; 87 FR 17945, Mar. 29, 2022; 87 FR 76421, Dec. 14, 2022; 89 FR 14410, Feb. 27, 2024]