StacksVerified U.S. regulatory reference

21 CFR §520.90c

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)Specifications. Each bolus contains ampicillin trihydrate equivalent to 400 milligrams of ampicillin.
  2. (b)Sponsor. See No. 054771 in § 510.600(c) of this chapter.
  3. (c)Related tolerances. See § 556.40 of this chapter.
  4. (d)Conditions of use in nonruminating calves—(1) Amount. 5 milligrams per pound of body weight twice daily not to exceed 4 days.
    1. (2)Indications for use. Oral treatment of bacterial enteritis (colibacillosis) caused by E. coli.
    2. (3)Limitations. Treated calves must not be slaughtered for food during treatment and for 7 days after the last treatment. Federal law restricts this drug to use by or on the order of a licensed veterinarian.