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Dry-Clox (Canada)

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


This treatment applies to the following species:
Company: Boehringer

Cloxacillin Benzathine

For intramammary infusion into the dry cow

Veterinary Use Only

DIN 02173247


Dry-Clox (cloxacillin benzathine) for INTRAMAMMARY INFUSION into the DRY COW is a product which provides bactericidal activity against gram-positive bacteria. The active agent, cloxacillin benzathine, is a sparingly soluble salt of the semisynthetic penicillin, cloxacillin. Cloxacillin is a derivative of 6-amino-penicillanic acid, and therefore is chemically related to other penicillins. It has, however, the antibacterial properties described below, which distinguish it from certain other penicillins.

Active Ingredient

Each 10 mL disposable syringe contains cloxacillin benzathine equivalent to 500 mg of cloxacillin activity in a stable peanut oil gel.


Do not store above 25°C. Do not freeze.

Action: In the non-lactating mammary gland, Dry-Clox provides bactericidal levels of the active antibiotic, cloxacillin, for a prolonged period of time. This prolonged activity is due to the low solubility of the cloxacillin benzathine and to the slow-release oil-gel base. This prolonged contact between the antibiotic and the pathogenic organism enhances the probability of a bacteriological cure.

Cloxacillin is not destroyed by the enzyme, penicillinase, and therefore, is active against penicillin-resistant strains of Staphylococcus aureus. It is also active against non-penicillinase-producing Staphylococcus aureus as well as Streptococcus agalactiae.

The class disc, Methicillin 5 mcg, should be used to estimate the in vitro susceptibility of bacteria to cloxacillin.

Dry-Clox Indications

For the treatment of mastitis caused by Streptococcus agalactiae and Staphylococcus aureus in dairy cows during the dry period.

Dry-Clox has been shown by extensive clinical studies to be efficacious in the treatment of mastitis in dry cows, when caused by Streptococcus agalactiae and Staphylococcus aureus including penicillin-resistant strains.

Treatment of the dry cow with Dry-Clox is indicated in any cow known to harbour any of these organisms in the udder at drying off, or which has had repeated attacks of mastitis during the previous lactation, or is affected with mastitis at drying off, if caused by susceptible organisms.

Directions For Use

Dry-Clox (cloxacillin benzathine) is for use in dry cows only. Infuse the contents of one syringe (10 mL) into each quarter immediately following the last milking or early in the dry period. Use no later than 30 days prior to calving.

Completely milk out all four quarters. The udder and teats should be thoroughly washed with warm water containing a suitable dairy antiseptic and dried, 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.

Dry-Clox is packaged with a protective cap.

For partial insertion: Twist off upper portion of the 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 syringe into the 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 protective cap is broken or damaged.

Dry-Clox Caution

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


This product must not be used in lactating dairy cows. Use immediately after drying off but not less than 30 days before the expected calving date. Treated animals must not be slaughtered for use in food for at least 30 days after the latest treatment with this drug. Milk taken from treated cows which calve within 30 days of infusion must not be used as food until the unexpired remainder of the 30 days has elapsed. Peanut Allergy Warning: This product contains peanut oil. KEEP OUT OF REACH OF CHILDREN.

Supply: Dry-Clox (cloxacillin benzathine) for INTRAMAMMARY INFUSION into the DRY COW. Cloxacillin benzathine equivalent to 500 mg of cloxacillin activity per syringe.

Carton containing 24 x 10 mL syringes. Pail containing 144 syringes.

Dry-Clox is a registered trademark of Boehringer Ingelheim Vetmedica, Inc., used under license.

Boehringer Ingelheim (Canada) Ltd., 5180 South Service Road, Burlington, Ontario L7L 5H4



CPN: 1230077.3

Customer Care No.:   1-800-567-1885
Technical Services No.:   1-877-565-5501
Every effort has been made to ensure the accuracy of the Dry-Clox information published above. However, it remains the responsibility of the readers to familiarize themselves with the product information contained on the Canadian product label or package insert.

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