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This page contains information on PolyMast for veterinary use.
The information provided typically includes the following:
  • PolyMast Indications
  • Warnings and cautions for PolyMast
  • Direction and dosage information for PolyMast


This treatment applies to the following species:
Company: Boehringer Ingelheim

(hetacillin potassium)

Intramammary Infusion

For lactating cows only

NADA 055-054, Approved by FDA

PolyMast Caution

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


PolyMast (hetacillin potassium) is a broad-spectrum agent which provides bactericidal activity against a wide range of common gram-positive and gram-negative bacteria. It is derived from 6- aminopenicillanic acid and is chemically related to ampicillin.

Each 10 mL disposable syringe contains hetacillin potassium equivalent to 62.5 mg ampicillin activity in a stable peanut oil gel. This product was manufactured by a non-sterilizing process.

Action: Hetacillin provides bactericidal levels of the active antibiotic, ampicillin. In vitro studies have demonstrated susceptibility of the following organisms to ampicillin: Streptococcus agalactiae, Streptococcus dysgalactiae, Staphylococcus aureus and Escherichia coli.

Indications: For the treatment of acute, chronic or subclinical bovine mastitis. PolyMast (hetacillin potassium) for Intramammary Infusion should be used at the first signs of inflammation or at the first indication of any alteration in the milk. Subclinical infections should be treated immediately upon determining, by C.M.T. or other tests, that the leukocyte count is elevated, or that a susceptible pathogen has been cultured from the milk.

PolyMast for Intramammary Infusion has been shown to be efficacious in the treatment of mastitis in lactating cows caused by susceptible strains of Streptococcus agalactiae, Streptococcus dysgalactiae, Staphylococcus aureus and Escherichia coli.

Polycillin® (ampicillin) Susceptibility Test Discs, 10 mcg, should be used to estimate the in vitro susceptibility of bacteria to hetacillin.

Dosage and Administration

Infuse the entire contents of one syringe (10 mL) into each infected quarter. Repeat at 24-hour intervals until a maximum of three treatments has been given.

If definite improvement is not noted within 48 hours after treatment, the causal organism should be further investigated.

Wash the udder and teats thoroughly with warm water containing a suitable dairy antiseptic and dry, preferably using individual paper towels. Carefully scrub the teat end and orifice with 70% alcohol, using a separate swab for each teat. Allow to dry.

PolyMast (hetacillin potassium) is packaged with the Opti-Sert® Protective Cap.

For partial insertion: Twist off upper portion of the Opti-Sert Protective Cap to expose 3-4 mm of the syringe tip.

For full insertion: Remove protective cap to expose the full length of the syringe tip. Insert syringe tip into the teat canal and expel the entire contents of one syringe into each infected quarter. Withdraw the syringe and gently massage the quarter to distribute the medication.

Do not infuse contents of the mastitis syringe into the teat canal if the Opti-Sert Protective Cap is broken or damaged.

Residue Warnings: Milk that has been taken from animals during treatment and for 72 hours (6 milkings) after the latest treatment must not be used for food.

Treated animals must not be slaughtered for food until 10 days after the latest treatment.


Because it is a derivative of 6-aminopenicillanic acid, PolyMast has the potential for producing allergic reactions. Such reactions are rare; however, should they occur, treatment should be discontinued and the subject treated with antihistamines, pressor amines, such as epinephrine or corticosteroids.

The drug does not resist destruction by penicillinase and, hence, is not effective against strains of staphylococcus resistant to penicillin G.


Do not store above 25°C (77°F). Do not freeze.

How Supplied

PolyMast (hetacillin potassium) Intramammary Infusion is supplied as 10 mL syringes containing 62.5 mg ampicillin activity per syringe. One display carton contains 12 syringes. One pail contains 144 syringes.

NDC 0010-4722-01 - 10 mL syringe; NDC 0010-4722-02 - 12 syringes; NDC 0010-4722-03 - 144 syringes.

Opti-Sert is a registered trademark of Zoetis W LLC - used under license.

PolyMast is a trademark of Boehringer Ingelheim Vetmedica GmbH, used under license.

© 2015 Boehringer Ingelheim Vetmedica, Inc. All Rights Reserved.

Made in Italy



Manufactured for: Boehringer Ingelheim Vetmedica, Inc., St. Joseph, MO 64506 U.S.A.

CPN: 1028305.0

Telephone:   800-325-9167
Fax:   816-236-2717
Every effort has been made to ensure the accuracy of the PolyMast information published above. However, it remains the responsibility of the readers to familiarize themselves with the product information contained on the US product label or package insert.

Copyright © 2020 Animalytix LLC. Updated: 2020-10-21