Fluid in the Mare's Uterus After Breeding: What It Means
In short. A little fluid in the hours after covering is normal; a healthy uterus clears it within about 48 hours. Fluid that is still there…
Knowledge & Science
Mare Fertility and Endometritis Blog
Articles and news on equine reproductive health
Is My Mare Too Old to Breed? The Older Mare Work-Up
In short. Age alone rarely stops a mare from getting in foal. What age does is lower the uterus's ability to clear fluid and bacteria after…
Repeated Early Embryonic Loss in Mares: Causes and Work-Up
In short. One early loss is common and usually not investigated. Two or more in the same mare are a pattern, and a pattern has a cause:…
Uterine Swab vs Lavage vs Biopsy: Which Finds the Infection?
In short. The swab samples the surface and is the least sensitive; the low-volume lavage samples the whole lining and finds more; the…
Mare Absorbed at 30 Days: Signs, Causes, Next Steps
On day 15 after covering, the scan shows a vesicle. Two weeks later the vesicle is gone, the mare is back in season, and nobody noticed a…
Mare Not Getting in Foal: What to Do, and in What Order
A mare that does not get in foal is not a rare case, but an expensive one: every cycle costs time, semen, vet visits and a slice of the…
Your Mare Is Activation-Positive: What Happens Next
A positive post-activation culture means that dormant bacteria, almost always Streptococcus zooepidemicus, were sitting in the uterus and…
Ultrasound of the Empty Mare: What the Vet Sees
The pregnancy check is done by ultrasound about two weeks after ovulation. When the probe shows no vesicle, the mare is empty. But the…
Uterine Lavage in the Mare: When and Why
A uterine lavage (uterine flush) is a treatment carried out by the veterinarian: body-warm fluid is run into the uterus through a catheter…
Streptococcus zooepidemicus in Horses: Symptoms & Treatment
Streptococcus equi subspecies zooepidemicus, usually shortened to Strep zoo, is one of the most common bacteria involved in disease in…
Culture Came Back Clean, but She Still Didn't Take
Many breeders know the pattern. The mare returns a clean uterine swab, the vet clears her for breeding, she is covered, and she still does…
What Is Biofilm in a Mare's Uterus, and Why It Is Not Enough
Breeders and vets increasingly talk about "biofilm" when a mare will not get in foal. It is a real phenomenon, but the common response,…
Why Antibiotics Fail on Dormant Bacteria, and Why the Culture Has to Come First
In short. Antibiotics act on bacteria that are dividing. Dormant Streptococcus zooepidemicus in the uterine lining is not, so it tolerates…
The Problem Mare: Why She Stays Empty and What to Check First
A problem mare is a mare that keeps failing to conceive despite normal cycles, a fertile stallion and clean routine swabs. In the published…
Taming the Troublemaker: A Guide to Handling Endometritis in Mares
In short. Endometritis in mares is most often caused by Streptococcus zooepidemicus, and in problem mares the bacteria are frequently…
What an Empty Season Costs: The Breeder's Calculation
A mare that does not get in foal costs more than the invoices that arrive for her. She costs a year of keep without a foal, a foal that…
Insights from a Landmark German Study: The Bacterial Spectrum in Mare Uterine Health
In short. In 28,887 endometrial samples from mares analysed in Germany (K hne et al., 2024), 25.9% grew potentially pathogenic bacteria,…
bActivate Demonstrates Remarkable Improvement in Fertility Rates for Thoroughbred Mares
In short. At Kildangan Stud in Ireland (Godolphin), 19 problem Thoroughbred mares with an average age of 12.7 years and 6.3 barren cycles…