Section 520.443 - Chlortetracycline tablets and boluses(a)Specifications. Each tablet contains 25 milligrams (mg) chlortetracycline hydrochloride; each bolus contains 250 or 500 mg chlortetracycline hydrochloride.(b)Sponsors. See sponsors in § 510.600(c) of this chapter for use as in paragraph (d) of this section. (1) No. 069043 for use of a 250-mg bolus as in paragraph (d)(1) of this section.(2) No. 016592 for use of a 25-mg tablet as in paragraph (d)(2) of this section.(3) No. 016592 for use of a 500-mg bolus as in paragraph (d)(3) of this section.(c)Related tolerances. See § 556.150 of this chapter.(d)Conditions of use in calves - (1)Amount. One 250 milligram bolus per 50 pounds of body weight twice a day for 3 to 5 days. (i)Indications for use. Treatment of bacterial enteritis (scours) caused by Escherichia coli and bacterial pneumonia associated with Pasteurella spp., Klesbsiella spp., and Haemophilus spp.(ii)Limitations. Administer bolus directly by mouth or crush and dissolve in milk or water for drenching or bucket feeding. Do not use for more than 5 days. Do not administer within 24 hours of slaughter. Federal law restricts this drug to use by or on the order of a licensed veterinarian.(2)Amount. One 25 milligram tablet for each 5 pounds of body weight every 12 hours daily for 3 to 5 days. (i)Indications for use. Control and treatment of bacterial enteritis (scours) caused by E. coli and Salmonella spp. and bacterial pneumonia associated with Pasteurella spp., Haemophilus spp., and Klebsiella spp., susceptible to chlortetracycline.(ii)Limitations. Administer tablet directly by mouth or crush and dissolve in water for drenching; if no improvement is noted after 3 days of treatment, consult a veterinarian; do not use for more than 5 days; when feeding milk or milk replacer, administration 1 hour before or 2 hours after feeding; do not administer within 24 hours of slaughter. Federal law restricts this drug to use by or on the order of a licensed veterinarian.(3)Amount. One 500 milligram bolus per 100 pounds of body weight twice a day for 3 to 5 days.(i)Indications for use. Treatment of bacterial enteritis (scours) caused by E. coli and Salmonella spp., and bacterial pneumonia associated with Pasteurella spp., Haemophilus spp., and Klebsiella spp., susceptible to chlortetracycline.(ii)Limitations. Do not use for more than 5 days. Do not administer within 24 hours of slaughter. Federal law restricts this drug to use by or on the order of a licensed veterinarian.57 FR 37325, Aug. 18, 1992, as amended at 67 FR 78355, Dec. 24, 2002. Redesignated and amended at 76 FR 49649, Aug. 11, 2011; 78 FR 21059, Apr. 9, 2013; 81 FR 17607, Mar. 30, 2016; 88 FR 16547, Mar. 20, 2023; 88 FR 27698, May 3, 2023; 88 FR 55563, Aug. 16, 2023 81 FR 17607, 3/30/2016; 83 FR 48944, 9/28/2018; 88 FR 16547, 3/20/2023; 88 FR 27698, 5/3/2023; 88 FR 55563, 8/16/2023