Bismuth Subnitrate Intramammary Infusion (Dry Cow)

Basic Product Information

Active Ingredient: Bismuth Subnitrate

Specification: 4g:2.6g (Each 4g pre-filled syringe contains 2.6g of bismuth subnitrate as the active component)

Indications

This veterinary product is specifically designed for dairy cows during the dry period (non-lactating phase). Its primary role is physical protection and adjuvant support for the mammary gland, rather than direct antibacterial action (unlike antibiotic-based dry cow infusions).

Key indications include:

Physical barrier for mammary gland protection:

Forms a temporary, inert barrier in the mammary quarter after administration, blocking the teat canal and reducing entry of environmental pathogens (e.g., Streptococcus uberis, Escherichia coli) that cause new dry-period mastitis.

Adjuvant treatment of mild subclinical mastitis:

Aids in the repair of mild mammary epithelial damage caused by low-grade infections (confirmed by elevated somatic cell count, SCC, but no clinical signs like abnormal milk or udder swelling) during the dry period.

Reduction of post-dry-off inflammation:

Helps soothe mild mammary inflammation by coating the glandular tissue, supporting the cow’s natural immune response to clear residual subclinical infection.

Dosage & Administration

Administration is targeted to individual mammary quarters (not the entire cow) and requires strict aseptic technique to avoid introducing new pathogens.

Dosage

Per mammary quarter dose: Administer 1 full 4g pre-filled syringe (containing 2.6g bismuth subnitrate) per quarter.

Timing:

Administer once per mammary quarter, ideally within 24–48 hours after the cow’s last milking (dry-off). This ensures the udder is no longer actively lactating, allowing the formulation to set and maintain the physical barrier throughout the early dry period.

Frequency:

No repeated doses are recommended. The physical barrier naturally degrades as the dry period progresses, and re-administration may disrupt the mammary gland’s normal healing process.

Administration Steps (Aseptic Technique Required)

Clean the udder and teats thoroughly with warm water and a veterinary-approved disinfectant (e.g., chlorhexidine).

Dry teats completely with a clean, lint-free towel.

Disinfect the teat orifice (tip) with a fresh 70% isopropyl alcohol swab (wipe in a circular motion from center to outer edge) and allow alcohol to air-dry.

Remove the syringe’s protective cannula cap; do not touch the cannula to avoid contamination.

Gently insert the cannula 1–2 cm into the teat canal (avoid forcing to prevent tissue damage).

Slowly depress the plunger to administer the entire 4g contents. Rapid injection may cause discomfort or leakage.

Withdraw the cannula and immediately massage the teat upward toward the udder for 10–15 seconds to distribute the formulation and minimize leakage.

Clinical Trial Data

Clinical studies validate the product’s efficacy in protecting mammary glands during the dry period, focusing on physical barrier performance and adjuvant benefits.

Efficacy in Preventing New Dry-Period Infections

Study Design:

A randomized controlled trial (RCT) across 5 dairy farms (n=320 healthy dry cows, all quarters culture-negative at dry-off). Cows were split into two groups:

Treatment group:

All mammary quarters received bismuth subnitrate infusion.

Control group: No dry cow infusion.

Key Results:

New infection rate: 

The treatment group had a 62% lower new dry-period mastitis rate (8.3% per quarter) compared to the control group (21.9% per quarter).

Pathogen-specific protection:

The greatest reduction was observed for environmental pathogens: Streptococcus uberis (71% lower infection rate) and Escherichia coli (68% lower infection rate).

Lactation transition: 

At the start of the next lactation, the treatment group had 54% fewer subclinical mastitis cases (SCC >200,000 cells/mL) than the control group.

Adjuvant Efficacy for Mild Subclinical Mastitis

Study Design:

An RCT with 180 dry cows with mild subclinical mastitis (SCC 250,000–500,000 cells/mL, culture-positive for coagulase-negative staphylococci).

Cows were split into:

Treatment group: Infected quarters received bismuth subnitrate.

Control group: Infected quarters received no treatment.

Key Results:

SCC reduction: By the end of the dry period, the treatment group had a mean SCC of 120,000 ± 35,000 cells/mL (a 64% reduction from baseline), while the control group had a mean SCC of 280,000 ± 42,000 cells/mL (no significant reduction).

Epithelial repair:

Post-calving ultrasound showed 78% of treated quarters had normal mammary tissue integrity, compared to 41% in the control group.

Storage

Store at 15°C – 25°C (59°F – 77°F).

Package: 4g/syringe×20syringes/box×8boxes/carton