Section 520.2613 - Trimethoprim and sulfadiazine powder(a)Specifications. Each gram of powder contains 67 milligrams (mg) trimethoprim and 333 mg sulfadiazine.(b)Sponsors. See Nos. 054771 and 059051 in § 510.600(c) of this chapter.(c)Conditions of use in horses - (1)Amount. Administer orally 3.75 grams of powder per 110 pounds (50 kilograms) of body weight in a small amount of feed, as a single daily dose, for 5 to 7 days.(2)Indications for use. For control of bacterial infections of horses during treatment of acute strangles, respiratory tract infections, acute urogenital infections, wound infections, and abscesses.(3)Limitations. Do not use in horses intended for human consumption. Federal law restricts this drug to use by or on the order of a licensed veterinarian.58 FR 36135, July 6, 1993, as amended at 64 FR 68289, Dec. 7, 1999; 79 FR 28834 , May 20, 2014; 79 FR 64116 , Oct. 28, 2014