Ultrasound Reveals Mare Retained Placenta Problems at Farms

For horse breeders and farm managers, foaling season is both exciting and stressful. Every birth brings joy and promise—but also potential complications. One of the more serious issues that can sneak up on even experienced breeders is retained placenta in mares. If not handled promptly, it can lead to life-threatening infections and fertility problems down the road. That’s where ultrasound has quietly become a game-changer.

Understanding Retained Placenta in Mares

Normally, after a mare gives birth, the placenta should be expelled within three hours. When it doesn’t, that’s what veterinarians call a retained placenta. It’s more common in draft breeds and older mares, but truthfully, no mare is totally immune. What makes this condition so tricky is that the symptoms aren’t always obvious—especially in the early stages. A mare might look completely fine for several hours after foaling, but infection can develop rapidly.

Traditionally, diagnosis relied on physical examination and visible signs like foul-smelling discharge, fever, or swelling. But by that point, the condition might already be causing internal damage. Ultrasound offers a way to spot the problem earlier—sometimes even before any outward signs appear.

How Farms Use Ultrasound to Detect Retained Placenta

On farms with access to veterinary ultrasound, we can now take a quick scan of the mare’s uterus within hours after foaling. What we’re looking for are remnants of placental tissue or abnormal fluid retention. The image gives a real-time view of what’s going on inside the uterus, and it helps answer critical questions:

• Is the placenta fully expelled?

• Is there any fluid buildup that suggests infection?

• Are the uterine walls contracting properly to clear out remaining tissue?

It’s a huge upgrade from just feeling around manually. With a probe placed transabdominally or transrectally (depending on the case), vets can zoom in on areas that might otherwise go unnoticed.

Why This Matters for Mare Health and Future Breeding

A retained placenta can lead to metritis (uterine infection), laminitis (inflammation of the hoof tissue), or even sepsis. These are not minor complications—some mares never recover fully, and in rare cases, it can even be fatal.

Ultrasound allows us to act early. If we see retained tissue or unusual fluid, we can flush the uterus, administer antibiotics, and start anti-inflammatory treatment right away. This quick response often prevents the situation from escalating.

More importantly, using ultrasound helps protect a mare’s long-term fertility. In the past, we might wait for a fever to appear before intervening. Now, we’re ahead of the game, preserving not only her health but her value in a breeding program.

Real Farm Experiences: What Horse Owners Are Saying

Many breeders in the U.S., the U.K., and Australia now swear by post-foaling ultrasounds. Emily, who runs a sport horse breeding operation in Kentucky, says:

“We started scanning mares a few hours after birth, just as a precaution. One time, our mare looked totally normal—but the ultrasound showed a small piece of placenta still attached. We flushed her immediately and avoided a whole mess.”

Similarly, breeders in Europe are adding ultrasound to their postnatal checklist. It’s becoming as routine as checking the foal’s IgG levels or ensuring they stand to nurse.

Beyond Diagnosis: Tracking Uterine Recovery

Ultrasound doesn’t just detect problems—it also helps track recovery. After treatment for retained placenta, follow-up scans show whether the uterus is clearing out properly. This kind of monitoring used to be a guessing game based on how the mare was acting. Now, it’s visual and measurable.

Many vets recommend a follow-up ultrasound 48 to 72 hours after treatment. If there’s still fluid or swelling, additional flushing or medication might be necessary. If things look clear, the mare can be safely rebred in the next cycle.

When to Scan: Timing is Everything

The best time to do a scan is within 2–4 hours after the foal is born. Even if the placenta appears to come out normally, a scan is still worth doing. Retained fragments can be just as dangerous as an entire retained placenta.

Veterinarians often combine this scan with a general postnatal health check for the mare, looking at uterine tone, cervical closure, and presence of any free fluid. It’s all part of a growing focus on proactive care rather than reactive treatments.

The Cost vs. the Consequences

One question many farm owners ask is: “Is it really worth paying for an ultrasound when everything seems fine?”

The answer, more often than not, is yes.

Treating a mare with full-blown infection is costly, both financially and reproductively. She might be out for the season—or worse, permanently infertile. A quick, affordable scan provides peace of mind and prevents a long list of complications. It’s the veterinary version of “an ounce of prevention is worth a pound of cure.”

Ultrasound and the Human Touch

Despite all the technology, it’s not about replacing skilled hands and experience. Ultrasound just gives vets another layer of insight—one that can’t be felt or seen with the naked eye. Combined with good observation and management, it’s a tool that supports, rather than replaces, the care provided by humans on the ground.

Limitations and Challenges

It’s important to note that ultrasound isn’t perfect. There are times when retained placenta can still be missed, especially if the tissue is very small or deeply embedded. Also, access to high-quality ultrasound machines and trained operators varies across farms, especially in more remote regions.

Still, the trend is clear. As equipment becomes more portable and affordable, more farms are integrating ultrasound into their standard foaling protocols. And for good reason—it helps save mares, foals, and future breeding opportunities.

The Future of Equine Postpartum Care

Looking ahead, ultrasound could become even more predictive. Research is underway to develop scanning protocols that might detect risk factors before a mare gives birth—such as poor uterine tone or abnormal placental thickness.

Veterinary schools are now teaching postnatal scanning as part of core reproductive training, which means more practitioners will be comfortable using this tool in the field. And as more farms track health data with digital records, combining ultrasound results with history could lead to smarter breeding decisions long-term.

Final Thoughts

What used to be a reactive, wait-and-see approach to retained placenta is now being replaced by precision, timing, and real-time imaging. Farms that use ultrasound proactively after foaling are not just preventing illness—they’re protecting their investment, improving animal welfare, and setting their breeding programs up for long-term success.

Veterinary ultrasound is no longer just for diagnosing pregnancy—it’s a powerful ally in the hours that matter most after a foal hits the ground.