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


This treatment applies to the following species:
Company: US Vet

(penicillin G procaine in sesame oil)

100,000 units/10mL Syringe

For Intramammary Infusion in Lactating Cows Only


NDC 86108-014-10


Each syringe contains:

100,000 units of penicillin G procaine, sesame oil 8.7g, calcium carbonate 0.089g, corn starch 0.089g, hydrogenated castor oil 0.044g.

Masti-Clear Indications

This product is intended for the treatment of bovine mastitis in lactating cows. This product is effective against udder infection caused by the following susceptible microorganisms:

Streptococcus agalactiae, Streptococcus dysgalactiae and Streptococcus uberis.

For the best results, it should be used promptly at the first signs of mastitis.

Signs of mastitis include:

1. Inflammation of the udder or teat. Inflammation may be recognized by redness, swelling, elevated temperature, or pain in the affected part.

2. Abnormal milk. Presence of flakes or clots in the milk, or milk of a watery character is usually indicative of a mastitis infection.

3. High white-cell counts. The routine use of the California Mastitis Test is encouraged. A high incidence of scores in excess of CMT 2 or a high CMT score on bulk milk samples may indicate a potential mastitis problem. In these situations a veterinarian should be consulted for definitive diagnosis and recommendations.

Directions For Use

Dosage: The dose is 10mL of this product per infected quarter administered by intramammary infusion. Treatment may be repeated at intervals of 12 hours. Do not administer more than three consecutive doses.

Milk out udder completely. Wash udder and teats thoroughly with warm water containing a suitable dairy disinfectant. Dry thoroughly. The hands of the operator should be washed and dried before the administration of each treatment. Using the alcohol pads that are provided with each syringe wipe off teat, using a separate pad for each teat. Appropriate sanitation and management procedures to prevent and/or control bovine mastitis should be instituted.

When using this product remove plastic cover from tip of syringe and, while holding teat firmly, insert tip into streak canal; then push plunger and inject entire contents. After injection, grasp the end of the teat firmly, then gently massage the medication up the teat canal into the milk cistern.

Treated quarters should not be milked for at least six hours after treatment but should be milked at regular intervals thereafter. Treatment may be repeated at 12 hour intervals, up to a total of three doses, as indicated by the clinical response.

NOTE: Mastitis cannot be considered cured until bacteriologic examination of milk samples taken approximately three weeks after treatment demonstrates the absence of causative microorganisms.


1. Discard all milk for 60 hours (5 milkings) after the latest treatment.

2. Animals intended for human consumption must not be slaughtered within 3 days of the last treatment with Masti-Clear®.

3. Use of this product in a manner other than as directed in the labeling might result in violative residues.


Keep out of reach of children. Discard empty container; do not reuse. It is a violation of Federal law to use Masti-Clear® in food-producing animals other than as directed in the labeling. If abnormal milk, redness, or swelling persists or increases, discontinue use and consult your veterinarian.

User Safety Warnings

Penicillins can cause allergic reactions in sensitized individuals. Topical exposure to penicillin may elicit mild to severe allergic reactions in some individuals. Repeated or prolonged exposure may lead to sensitization. Avoid direct contact of the product with the skin, eyes, mouth and clothing.

Persons with known hypersensitivity to penicillin should avoid exposure to this product.

In case of accidental eye exposure, flush with water for 15 minutes. In case of accidental skin exposure, wash with soap and water. Remove contaminated clothing. If allergic reaction occurs (e.g., skin rash, hives, difficult breathing), seek medical attention.

The material safety data sheet contains more detailed occupational safety information.

To report side effects in users, to obtain more information or to obtain a Material Safety Data Sheet, call 1-866-562-4708.




Manufactured for: US VET Inc., Hamilton, NY 13346

Approved by FDA under NADA # 065-081

INS012LC 11

Rev. 01/2020

CPN: 2093003.0

120 ROUTE 17 NORTH, PARAMUS, NJ, 07652
Customer Service:   833-551-0306
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.

Copyright © 2023 Animalytix LLC. Updated: 2023-02-28