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Boehringer Ingelheim

Synanthic Bovine Suspension Dewormer

Synanthic Bovine Suspension Dewormer

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Synanthic (oxfendazole) Bovine Dewormer Suspension for Cattle is broad-spectrum oral cattle dewormer for the treatment and control of lungworms, all major roundworms, nodular worms, tapeworms and inhibited ostertagia. Readily absorbed for fast and effective control—absorbed in the gastrointestinal tract reaching peak potency within 20 hours post-administration. Low-volume, concentrated dosing allows more treatments per bottle. The active ingredient, oxfendazole 22.5% removes and controls multiple species of stomach worms and intestinal worms, lungworm, and tapeworm. Labeled for: beef and dairy cattle (do not use female dairy cattle of breeding age), and calves.

Dosage: Administer orally. Administer 1 ml per 110 lbs body weight. 1 liter treats 200 - 550 lb cattle. Synanthic dewormer has no known resistance issues. 7 day slaughter withdrawal. Do not use in female dairy cattle of breeding age.

Controls and treats the following parasites:
Stomach worms: brown stomach worms (Ostertagia ostertagi; adult, L4, inhibited L4), barberpole worms (Haemonchus contortus; adult), Haemonchus placei (Adult), small stomach worms (Trichostrongylus axei; adult).
Intestinal Worms: small intestinal worms (Cooperia punctata; adult, L4), Cooperia oncophora (adult, L4), Cooperia surnabada (adult, L4), nodular worms (Oesophagostomum radiatum; adult), hookworms, (Bunostomum phlebotomum; adult).
Lungworms: Dictyocaulus viviparus (adult, L4).
Tapeworms: Moniezia benedeni (adult).

Manufacturer and/or Label Information

Telephone: 800-325-9167
Customer Service: 888-637-4251
Technical Service: 888-637-4251
Fax: 816-236-2717
THIS SERVICE AND DATA ARE PROVIDED "AS IS". DVMetrics assumes no liability, and each user assumes full risk, responsibility, and liability, related to its use of the DVMetrics service and data. See the Terms of Use for further details.

Boehringer Ingelheim Animal Health

(oxfendazole oral suspension)

Bovine Dewormer Suspension, 22.5%

For Animal Use Only

Approved by FDA under NADA # 140-854

Each mL contains 225 mg of oxfendazole.

Consult a veterinarian for assistance in the diagnosis, treatment and control of parasitism.

Indications: SYNANTHIC Bovine Dewormer Suspension, 22.5%, is a broad-spectrum anthelmintic effective for the removal and control of the following parasites in cattle: lungworms, roundworms (including inhibited forms of Ostertagia ostertagi) and tapeworms, as indicated below:

Lungworms: Dictyocaulus viviparus (Adult, L4)

Stomach Worms:

Barberpole Worms - Haemonchus contortus (Adult)

Haemonchus placei (Adult)

Small Stomach Worms - Trichostrongylus axei (Adult)

Brown Stomach Worms - Ostertagia ostertagi (Adult, L4, inhibited L4)

Intestinal Worms:

Nodular Worms - Oesophagostomum radiatum (Adult)

Hookworms - Bunostomum phlebotomum (Adult)

Small Intestinal Worms - Cooperia punctata (Adult, L4)

Cooperia oncophora (Adult, L4)

Cooperia surnabada (Adult, L4)

Tapeworms - Moniezia benedeni (Adult)

Administration and Dosage: SYNANTHIC Bovine Dewormer Suspension, 22.5%, is supplied in 500 mL and one liter packages containing 225 mg of oxfendazole per mL. The recommended dose for cattle is 2.05 mg/lb (4.5 mg/kg) of body weight. SYNANTHIC Bovine Dewormer Suspension, 22.5%, should be administered orally by accurate dose syringe at the rate of 1 mL per 110 lb (50 kg) of body weight. This product should be shaken well immediately prior to use. Do not underdose. Ensure each animal receives a complete dose based on a current body weight. Underdosing may result in ineffective treatment, and encourage the development of parasite resistance.

Remove Cap and Protective Seal and Replace with Draw Off Cap Prior to Use. Do Not Squeeze Sides of Bottle. Replace the Draw Off Cap with the Initial Cap after Use.

Directions: Determine the proper dose according to estimated body weight. Administer orally. The recommended dose of 2.05 mg/lb (4.5 mg/kg) is achieved when 1 mL of the suspension is given for each 110 lb (50 kg) of body weight.


Cattle Weight


110 lb (50 kg)

1.0 mL

220 lb (100 kg)

2.0 mL

330 lb (150 kg)

3.0 mL

440 lb (200 kg)

4.0 mL

550 lb (250 kg)

5.0 mL

660 lb (300 kg)

6.0 mL

770 lb (350 kg)

7.0 mL

880 lb (400 kg)

8.0 mL

990 lb (450 kg)

9.0 mL

1100 lb (500 kg)

10.0 mL

Treatment may be repeated in 4-6 weeks.

Residue Warnings: Cattle must not be slaughtered until 7 days after treatment. Because a withdrawal time in milk has not been established, do not use in female dairy cattle of breeding age.

Other Warnings: Parasite resistance may develop to any dewormer, and has been reported for most classes of dewormers.

Treatment with a dewormer used in conjunction with parasite management practices appropriate to the geographic area and the animal(s) to be treated may slow the development of parasite resistance.

Fecal examinations or other diagnostic tests and parasite management history should be used to determine if the product is appropriate for the herd/flock, prior to the use of any dewormer. Following the use of any dewormer, effectiveness of treatment should be monitored (for example, with the use of a fecal egg count reduction test or another appropriate method).

A decrease in a drug’s effectiveness over time as calculated by fecal egg count reduction tests may indicate the development of resistance to the dewormer administered. Your parasite management plan should be adjusted accordingly based on regular monitoring.

Caution: Use only as directed. Keep out of reach of children. Not for human use.

Safety: There are no contraindications for the use of SYNANTHIC Bovine Dewormer Suspension, 22.5%, in cattle.

Shake well before use.

Storage: Store at or below 25°C (77°F). Brief excursions are permitted up to 30°C (86°F). Do not freeze.

Restricted Drug (California) - Use Only as Directed.

© 2019 Boehringer Ingelheim Animal Health USA Inc. All rights reserved.

SYNANTHIC and the Cattle Head Logo are registered trademarks of Boehringer Ingelheim Animal Health USA Inc.

Marketed by:

Boehringer Ingelheim Animal Health USA Inc., Duluth, GA 30096

Net Contents:


500 mL
The entire contents treats 110 cattle weighing approximately 500 lbs each.




1000 mL (1 liter)
The entire contents treats 220 cattle weighing approximately 500 lbs each.




CPN: 1028221.4

COLORADO SERUM COMPANY4950 YORK STREET, P.O. BOX 16428, DENVER, CO, 80216-0428Telephone: 303-295-7527Order Desk: 800-525-2065Fax: 303-295-1923Website: www.colorado-serum.comEmail: colorado-serum@colorado-serum.comTHIS SERVICE AND DATA ARE PROVIDED "AS IS". DVMetrics assumes no liability, and each user assumes full risk, responsibility, and liability, related to its use of the DVMetrics service and data. See the Terms of Use for further details.


Colorado Serum


GENERAL INFORMATION: This product has been shown to be effective for the vaccination of healthy horses, cattle, sheep, goats, and swine against tetanus. This product was licensed prior to the requirement to establish a minimum age for use. The duration of immunity is unknown. For more information regarding efficacy and safety data, see

Safety in pregnant animals is unknown.

Tetanus Toxoid is prepared by detoxifying tetanus toxin in such a manner as to allow the antigenic properties to remain intact. Product is purified, concentrated and adjuvanted to provide a low dose effective immunizing agent.

Each serial is tested for purity, safety, and potency in accordance with USDA requirements.

Tetanus is caused by a neurotoxin produced by growth of Clostridium tetani, an anaerobic (lives without air) micro-organism, in necrotic tissue. Affected animals become stiff, have difficulty swallowing, and have an increased pulse rate. Breathing is labored. Spasmodic contractions of the muscular system occur, such as contracting muscles of the jaw.

Spasmodic contractions of the muscular system occur, such as contracting muscles of the jaw. Thus, the term “lockjaw” is often used. Legs and tail are often stiff with abdominal muscles contracted. Tetanus stricken animals may be unusually sensitive to light and heat. Temperature of the animal generally remains normal, elevating only shortly before death.

Protective antibody levels usually occur about two weeks after the second injection of the primary immunization series. In contrast, administration of Tetanus Antitoxin is recommended for immediate, emergency, passive treatment of exposed animals with unknown vaccination history or with signs of tetanus infection.

DIRECTIONS: Do not vaccinate within 21 days before slaughter. Store at 2-8° C. Do not freeze. Do not mix with other products. Shake well before use. Use entire contents when first opened.

PRECAUTIONS: A transitory local reaction may occur at injection site. Anaphylactoid reaction may occur following administration of products of this nature. If noted, administer adrenalin or equivalent. In case of human exposure, consult a physician.

DOSAGE & ADMINISTRATION: For primary immunization, two doses should be administered subcutaneously or intramuscularly approximately 30 days apart. Use intramuscularly for horses as local reactions are more likely to occur if injected subcutaneously.

Horses: 1 ml IM

Cattle: 1 ml SC or IM

Sheep, Goats, Swine: 0.5 ml SC or IM

Historically, annual single dose revaccination has been recommended. Contact veterinarian for advice.

OTHER INFORMATION: Contains thimerosal and formalin as preservatives. Tetanus Toxoid Concentrate is available in single dose size packaged 10 vials to the carton, and in 10 dose vials.


VLN: 188 / PCN: 8601.00

COLORADO SERUM COMPANY, 4950 York Street, Denver, Colorado 80216


Contact us for information on other Colorado Serum Company products. Fine Veterinary Products since 1923.




Order #

10 - 1 ml vials

10 - 1 dose vials


10 ml

10 doses


CPN: 1101033.3



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