(a) Specifications.

(1) Sodium sulfachlorpyridazine powder.

(2) Each bolus contains 2 grams sulfachlorpyridazine.

(3) Each tablet contains 250 milligrams (mg) sulfachlorpyridazine.

(b) Sponsor. See No. 016592 in §510.600(c) of this chapter.

(c) Related tolerances. See §556.630 of this chapter.

(d) Conditions of use. It is used as follows:

(1) Calves—(i) Amount. Administer 30 to 45 mg sulfachlorpyridazine powder per pound (/lb) of body weight per day in milk or milk replacer, or in a bolus, in divided doses twice daily for 1 to 5 days.

(ii) Indications for use. For the treatment of diarrhea caused or complicated by Escherichia coli (colibacillosis).

(iii) Limitations. Treated ruminating calves must not be slaughtered for food during treatment or for 7 days after the last treatment. A withdrawal period has not been established for this product in preruminating calves. Do not use in calves to be processed for veal. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

(2) Swine—(i) Amount. Administer 20 to 35 mg/lb body weight per day, in divided doses twice daily for 1 to 5 days:

(A) In drinking water or

(B) For individual treatment, in an oral suspension containing 50 mg per milliliter.

(ii) Indications for use. For the treatment of diarrhea caused or complicated by E. coli (colibacillosis).

(iii) Limitations. Treated swine must not be slaughtered for food during treatment or for 4 days after the last treatment. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

(3) Dogs—(i) Amount. Administer tablets orally at 500 mg per 10 to 15 lb of body weight daily, in two or three divided doses.

(ii) Indications for use. As an aid in the treatment of infectious tracheobronchitis and infections caused by E. coli, and in the treatment of infections caused by other Gram-positive and Gram-negative organisms that are susceptible to sulfonamide therapy.

(iii) Limitations. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

[75 FR 10166, Mar. 5, 2010, as amended at 79 FR 28829, May 20, 2014; 81 FR 17607, Mar. 30, 2016; 81 FR 94990, Dec. 27, 2016]