21 C.F.R. § 520.443
Chlortetracycline tablets and boluses.
Cite as 21 C.F.R. § 520.443 (2026)
(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]
- Cross-references to the CFR
- 510.600556.150