Section 520.1248 - Levothyroxine(a)Specifications. Each tablet contains 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or 1.0 milligrams (mg) levothyroxine sodium.(b)Sponsors. See Nos. 059051 and 061690 in § 510.600(c) of this chapter.(c)Conditions of use -(1)Amount. Administer by mouth as follows:(i) No. 061690: 0.1 mg/10 pounds (lb) body weight (0.022 mg/kilogram (kg)) as a single dose every 24 hours or as a divided dose every 12 hours.(ii) No. 059051: 0.1 mg/10 lb (0.01 mg/lb, 0.022 mg/kg) body weight twice daily.(2)Indications for use. For replacement therapy for diminished thyroid function in dogs.(3)Limitations. Federal law restricts this drug to use by or on the order of a licensed veterinarian. 81 FR 22523 , Apr. 18, 2016, as amended at 86 FR 57996 , Oct. 20, 2021 81 FR 22523, 4/18/2016; as amended at 86 FR 57996, 10/20/2021