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Solving Chronic Endometritis in Mares: Why Activating Dormant Bacteria Is the Key to Successful Treatment

21. March 2025

🧬 The Hidden Challenge: Dormant Bacteria Like Streptococcus zooepidemicus

In many mares, pathogenic bacteria such as Streptococcus zooepidemicus or E. coli lie dormant inside the uterus. They may not show up in swabs or cultures, and they may not trigger a strong immune response.

📉 That means:

  • Standard diagnostic tests may appear “clean”
  • Antibiotics may seem ineffective
  • Inflammation and fluid retention persist
  • Fertility drops dramatically

These dormant bacteria are inactive, not multiplying – which makes them resistant to antibiotics, since most antibiotics only work on bacteria that are actively growing.


✅ The Solution: Activate First, Then Treat

bActivate is not a probiotic. It’s a biological growth medium specifically designed to activate dormant bacteria – including Strep zoo.

Here’s the step-by-step process:

1. bActivate is administered intrauterine

It stimulates the reactivation of dormant bacteria, waking them up and pushing them into a metabolically active phase.

2. Within 24–48 hours, the bacteria begin to grow

This is a critical window, because now the pathogens are:
✔️ Detectable on culture
✔️ Biologically active
✔️ Susceptible to antibiotics

3. Targeted antibiotic therapy is then applied

At this point, treatment with penicillin or another targeted antibiotic can effectively eliminate the now-active infection.


💡 Why This Approach Works

By combining biological activation with targeted antibiotic treatment, you’re solving the problem from both ends:

🦠 bActivate exposes the hidden threat
💉 Antibiotics eliminate it effectively

This strategy is especially effective in:

  • Mares with recurrent or subclinical endometritis
  • Mares with a history of antibiotic failure
  • Mares showing fluid retention but clean swabs
  • Barren mares with no obvious reason for infertility

📈 Real-World Results

Breeders and veterinarians using this method report:
✔️ Improved diagnostic clarity
✔️ Better response to antibiotics
✔️ Reduced recurrence of infection
✔️ Higher conception rates in previously barren mares


🐴 Final Thoughts: Treat Smarter, Not Just Harder

If antibiotics alone haven’t worked, it’s not because they’re the wrong medicine — it might be because the bacteria you’re targeting aren’t awake.

bActivate makes them visible.
Antibiotics make them gone.

This dual-phase strategy represents a smarter, evidence-based solution to one of the most frustrating causes of mare infertility.


📞 Want to know how to integrate this protocol into your breeding program?
Get in touch with us today or speak to your veterinarian about using bActivate before antibiotic treatment.


Trusted by breeders & vets worldwide

What our clients say

Real results from veterinarians and breeders who have made bActivate part of their reproductive protocol.

Clinical Study
★★★★★

We incorporated bActivate into our standard reproductive work-up for problem mares at Hagyard. Out of 64 mares that had failed to conceive for at least 3 cycles, 83% became pregnant following bActivate activation and targeted antibiotic treatment. Nearly half had a dormant Streptococcus infection that standard culture had completely missed. It changed the way we approach the problem mare.

KL
Dr. Kristina Lu, DVM
Hagyard Equine Medical Institute, Lexington, Kentucky
Clinical Study
★★★★★

We used bActivate on 19 of our most persistent problem mares — horses that had been barren for over a year despite every conventional treatment we tried. 89% of them got in foal. What really opened our eyes was how many had a hidden infection that standard swabs had never detected. It is now a routine part of our protocol at Kildangan.

MO
Meta Osborn
Kildangan Stud, Godolphin
Breeder
★★★★★

We have been using bActivate on several mares — all got pregnant and most of them in first try with frozen semen!

JH
Jeanette Marina Hansen
Mare Owner & Breeder
Veterinarian
★★★★★

bActivate is an excellent tool that allows us as reproductive vets to do our job as effectively as possible. When you compare the cost to the expense of a mare that fails to conceive — or worse, never produces a foal — bActivate is both a smart and cost-effective solution in the long run.

LB
Lotte Bøgedal
Reproductive Veterinarian
Breeder
★★★★★

I used bActivate and after just one covering got a colt foal — after 3 years of hardship where the mare went in foal but never managed to produce a live foal. I cannot recommend bActivate enough.

MD
Mary Davison
Cathrinestown Stud Farm, Leixlip, Ireland

FAQ

Frequently Asked Questions

Common questions about problem mares, biofilm infections and bActivate treatment.