DESCRIPTION
Bottles of Vetisulid Powder (Sodium Sulfachlorpyridazine Powder) for oral use contain 54 g sodium sulfachlorpyridazine powder (equivalent to 50 g sulfachlorpyridazine).

ACTIONS
Sulfachlorpyridazine is a broad spectrum antibacterial compound which is effective in the treatment of infections caused by gram-positive and gram-negative organisms that are commonly susceptible to sulfonamide therapy and which has been proven by laboratory and field experiments to be highly effective against diseases caused by Escherichia coli.
Sulfachlorpyridazine has a rapid onset of action in several species of animals following both oral and parenteral administration. In comparison with other sulfonamides the administration of comparatively effective oral doses of sulfachlorpyridazine to dogs produces blood concentrations that reach maximum levels in 1 to 3 hours. The blood level declines to 1 to 2 mg-percent after 12 hours and the drug is completely excreted in the urine within 48 hours. In experimental studies in which cattle are given the recommended dosage of sulfachlorpyridazine intravenously the blood level rises to above 12 mg-percent within 1 hour and 6 hours later it falls to 3 to 4 mg-percent; after 18 hours no sulfonamide can be detected. In swine given the recommended dosage of sulfachlorpyridazine either intramuscularly or orally the blood level reaches 5.5 mg-percent after 1.5 hours. The blood level declines to 1 to 2 mg-percent within 6 hours; after 12 hours practically no sulfonamide can be detected. Laboratory studies with other species of animals have demonstrated similar responses in blood and urine following oral or parenteral administration of sulfachlorpyridazine.
Sulfachlorpyridazine is readily soluble at normal urinary pH making it unlikely that crystallization of the free and acetylated forms will occur.
Studies with laboratory animals indicate that sulfachlorpyridazine attains a high concentration in the bile; the concentrations in the liver and kidneys approximately parallel that of the blood thus demonstrating excellent penetration of tissues.
Veterinary laboratories have confirmed the exceptional activity of sulfachlorpyridazine against E. coli by both in vitro and in vivo tests. In one study 64 out of 70 E. coli strains that were isolated from clinical cases of colibacillosis in calves were sensitive to sulfachlorpyridazine. Another sensitivity study involving calves revealed 225 isolates of E. coli that were sensitive to sulfachlorpyridazine out of a total of 226 isolates examined. Pretreatment and post-treatment identifications of various serotypes of E. coli were made in this study. In all serotypes except one the number of isolates cultured from the feces of treated calves was reduced following treatment with sulfachlorpyridazine. Results from a study in swine revealed that 110 out of 118 strains of E. coli isolated from swine enteritis were sensitive to sulfachlorpyridazine. Clinical studies confirm its efficacy in treating E. coli infections.

INDICATIONS
Vetisulid Powder is especially indicated for the treatment of diarrhea caused or complicated by E. coli (colibacillosis) in calves under 1 month of age; Vetisulid Powder is also indicated for the treatment of colibacillosis in swine.

WARNING Treated ruminating calves must not be slaughtered for food during treatment and for 7 days after the last oral treatment. Treated swine must not be slaughtered for food during treatment and for 4 days after the last treatment.

WARNING: A withdrawal period has not been established for these products in pre-ruminating calves. Do not use in calves to be processed for veal.

CAUTION
The diagnosis should be reconfirmed if symptoms persist for 2 to 3 days.
To insure adequate urine flow and to prevent crystalluria water should be readily available to animals receiving sulfachlorpyridazine therapy.

DOSAGE AND ADMINISTRATION
Calves:
The recommended daily dose is 30 to 45 mg of sulfachlorpyridazine per lb of body weight administered in 2 divided doses for 1 to 5 days as follows: It is suggested that therapy be initiated by administering Vetisulid Injection (see package information accompanying that product for complete information) intravenously and continuing therapy with the oral administration of Vetisulid Powder.
Vetisulid Powder (Sodium Sulfachlorpyridazine Powder)-To prepare a solution for treatment mix the contents of a 54 g bottle of Vetisulid Powder (equivalent to 50 g sulfachlorpyridazine) with sufficient milk or milk substitute to treat a number of calves totaling 2200 to 3300 lb of body weight (e.g. 20 calves from 110 to 165 lb each). Use immediately. Administer fresh solution twice daily.
Example administration for a single calf: Each level teaspoon of Vetisulid Powder contains approximately 2800 mg of sulfachlorpyridazine. The daily dose of Vetisulid Powder is 30-45 mg per pound body weight divided into two equal treatments.
To treat a single 130 pound calf mix 3/4 teaspoon to 1 level teaspoon of Vetisulid Powder with sufficient milk or milk substitute to be consumed at one feeding. Repeat every 12 hours for up to 5 days duration. Mix Vetisulid Powder with milk just prior to each treatment.
Swine:
Vetisulid Powder-The recommended daily oral dose is 20 to 35 mg of sulfachlorpyridazine per lb of body weight administered in 2 divided doses for 1 to 5 days. The dose may be administered either individually or by herd treatment. Prepare fresh solution at time of use.
Individual Pig Treatment-To prepare a solution for treatment add the contents of a 54 g bottle of Vetisulid Powder to 5 cups (40 ounces) of water. Draw the prepared solution into a syringe graduated in milliliters and administer it to each pig orally using the following dosage schedule:

Important: When treating the pigs individually make certain the entire recommended dose is swallowed by each pig.
Herd Treatment-To prepare a solution for treatment add the contents of a 54 g bottle of Vetisulid Powder to 15 gallons of water. Since the daily water consumption of pigs varies tremendously that quantity of Vetisulid Powder medicated drinking water will treat the following numbers of pigs according to their body weight. Prepare fresh solution at time of use.

If the recommended quantity of medicated drinking water is consumed replace it with normal or unmedicated water until it is time for the next dose to be administered.

HOW SUPPLIED
Vetisulid Powder (Sodium Sulfachlorpyridazine Powder) bottles of 1.9 oz (54 grams) of powder.
NDC 53501-235-10 - 54 gm bottles.

STORAGE
Store at room temperature; avoid excessive heat (104°F).