StacksVerified U.S. regulatory reference

21 CFR §520.1720c

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)Specifications.
    1. (1)Each gram of paste contains 0.2 grams phenylbutazone.
    2. (2)Each gram of paste contains 0.35 grams phenylbutazone.
  2. (b)Sponsors. See sponsor numbers in § 510.600(c) of this chapter.
    1. (1)No. 000061 for use of product described in paragraph (a)(1) of this section.
    2. (2)No. 017030 for use of product described in paragraph (a)(2) of this section.
  3. (c)Conditions of use in horses—(1) Amount. 1 to 2 grams of phenylbutazone per 500 pounds of body weight, not to exceed 4 grams daily.
    1. (2)Indications for use. For relief of inflammatory conditions associated with the musculoskeletal system.
    2. (3)Limitations. Do not use in horses intended for human consumption. Federal law prohibits the use of this drug in female dairy cattle 20 months of age or older. Federal law restricts this drug to use by or on the order of a licensed veterinarian.