Obturator Nerve Paralysis in Horses: Splayed Hindlimbs and Foaling-Related Injury

Quick Answer
  • Obturator nerve paralysis is an uncommon but serious post-foaling nerve injury that can make a mare's hind legs slide outward into a wide, split-like stance.
  • It most often happens after a difficult or prolonged delivery, especially when a large foal, abnormal foal position, or strong traction puts pressure on nerves inside the pelvis.
  • See your vet promptly if a mare cannot stand, keeps slipping behind, seems painful, or had a hard foaling. Down mares can develop secondary muscle and nerve damage quickly.
  • Many mares improve with anti-inflammatory care, hobbling, traction on the floor, and careful support while the nerve recovers over days to weeks, but severe cases may need hospitalization or a sling.
  • Typical 2025-2026 US cost range is about $400-$1,200 for farm evaluation and initial supportive care, $1,500-$4,000 for standard hospital-based treatment, and $4,000-$10,000+ if prolonged hospitalization, advanced imaging, or intensive support is needed.
Estimated cost: $400–$10,000

What Is Obturator Nerve Paralysis in Horses?

Obturator nerve paralysis is a nerve injury that affects the muscles responsible for pulling the hindlimbs inward. When that nerve is damaged, the mare may be unable to keep her back legs under her body. The classic look is a wide-based stance or hindlimbs that slide outward on slick footing, sometimes immediately after foaling.

In horses, this problem is most often discussed as post-foaling paralysis or obstetrical paralysis. It is usually linked to pressure on nerves within the pelvic canal during parturition, especially after dystocia. The onset is typically immediate or within a few hours after delivery, and signs can range from mild stiffness to complete inability to stand.

Although the obturator nerve is the best-known nerve involved, some mares have more than one nerve affected after a difficult birth. That matters because a mare with combined nerve injury may be weaker, more unstable, and slower to recover than a mare with a more isolated obturator injury. Your vet will look for the full pattern of weakness before discussing prognosis and treatment options.

Symptoms of Obturator Nerve Paralysis in Horses

  • Hindlimbs splay outward or slide apart
  • Wide-based stance behind
  • Difficulty standing after foaling
  • Weak, short, or uncoordinated steps in the hind end
  • Recumbency or inability to remain standing
  • Minimal ability to adduct one or both hindlimbs
  • Recent history of dystocia, prolonged labor, or strong traction during delivery
  • Secondary abrasions, exhaustion, or distress from repeated slipping

See your vet immediately if a mare cannot stand, keeps doing the splits behind, seems increasingly painful, or had a difficult foaling. A mare that is down for long can develop muscle damage, pressure injuries, and additional nerve trauma.

It is also important not to assume every post-foaling hindlimb problem is obturator nerve paralysis. Pelvic fracture, coxofemoral luxation, severe soft tissue injury, uterine or abdominal emergencies, and other neurologic problems can look similar at first. That is why a prompt hands-on exam matters.

What Causes Obturator Nerve Paralysis in Horses?

The usual cause is compression or stretching of the obturator nerve during foaling. The nerve runs along the inside of the pelvis, which makes it vulnerable when a foal is lodged in the birth canal or when labor is prolonged. Difficult births, large foals, malformed foals, narrow pelvic conformation, and delayed correction of dystocia all increase risk.

Excessive traction during assisted delivery can add to the problem. Merck notes that excessive mechanical or manual traction should be avoided during dystocia management, and equine reproduction sources emphasize that timing is critical because prolonged manipulation increases trauma to the mare. In practical terms, the longer a mare strains against an obstructed delivery, the more pressure and swelling can affect the nerves and surrounding tissues.

Some mares have injury beyond the obturator nerve alone. Post-foaling paralysis can also involve the sciatic, gluteal, or, less commonly, femoral nerves. Hemorrhage, swelling, and muscle damage around the pelvis can worsen weakness. This is one reason two mares with a similar-looking wide stance may have very different recovery times.

Miniature horses and small mares carrying relatively large foals may face added dystocia risk. More broadly, any situation that makes delivery harder or longer can raise the chance of postpartum nerve injury. Prevention focuses less on the nerve itself and more on reducing foaling trauma overall.

How Is Obturator Nerve Paralysis in Horses Diagnosed?

Your vet usually diagnoses obturator nerve paralysis from the history and physical exam. The timing is often very suggestive: a mare foals, especially after dystocia, and then immediately or soon afterward cannot keep her hindlimbs under her. On exam, your vet will assess whether the mare can stand, how she places each hindlimb, whether one or both sides are affected, and whether other nerves may also be involved.

Diagnosis also means ruling out other serious problems. Radiographs may be recommended to look for pelvic or femoral fractures or hip luxation, especially if the mare is severely painful, asymmetric, or not improving as expected. Depending on the case, your vet may also check for postpartum complications such as retained fetal membranes, genital tract trauma, shock, or abdominal pain that could change the treatment plan.

In many field cases, advanced neurologic testing is not needed right away. What matters most is identifying whether the mare is stable, whether she can be safely supported, and whether there are orthopedic or reproductive emergencies happening at the same time. If the picture is unclear, referral to an equine hospital may be the safest next step.

Recovery can take days to weeks in mares that improve, so repeat exams are often part of the diagnostic process. If a mare remains recumbent, worsens, or develops complications, your vet may revise the prognosis and discuss more intensive support or humane endpoints.

Treatment Options for Obturator Nerve Paralysis in Horses

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Budget-Conscious Care

$400–$1,200
Best for: Mares that are bright, stable, and able to stand or be assisted safely in the field, with suspected mild to moderate obturator nerve injury and no evidence of fracture or other major postpartum emergency.
  • Urgent farm exam after foaling
  • Neurologic and musculoskeletal assessment
  • Anti-inflammatory medication chosen by your vet
  • Hindlimb hobbles or soft restraints to limit splaying
  • Deep, non-slip footing and careful standing confinement
  • Nursing care, assisted rising when safe, and close monitoring for retained placenta, pain, and laminitis risk
Expected outcome: Fair in selected cases. Many mares with uncomplicated nerve compression improve over days to weeks if they can stay standing and avoid repeated slipping.
Consider: Lower upfront cost, but it depends heavily on safe footing, frequent observation, and the mare's ability to avoid further injury. It may be inadequate for recumbent mares, severe bilateral weakness, or cases where imaging and hospital support are needed.
Most Common

Recommended Standard Treatment

$1,500–$4,000
Best for: Most mares with moderate weakness, repeated slipping, uncertain diagnosis, or concern for additional postpartum complications after dystocia.
  • Everything in conservative care plus hospital or intensive on-farm monitoring
  • Sedation and safer assisted standing as needed
  • Radiographs to rule out pelvic/femoral fracture or hip luxation when indicated
  • IV fluids or additional supportive care if exhausted or dehydrated
  • More structured anti-inflammatory plan and nursing care
  • Short-term sling support or controlled standing stall setup when appropriate
Expected outcome: Fair to guarded, depending on whether the mare can remain standing and whether only the obturator nerve is affected. About half of post-foaling paralysis cases are reported to recover in days to weeks.
Consider: More diagnostics and safer support improve decision-making, but costs rise with hospitalization, imaging, and hands-on nursing. Some mares still decline if nerve damage is severe or multiple nerves are involved.

Advanced / Critical Care

$4,000–$10,000
Best for: Recumbent mares, mares with severe bilateral paralysis, suspected multiple nerve involvement, major postpartum trauma, or cases not improving with initial treatment.
  • Referral hospital care with 24-hour monitoring
  • Repeated sling support or specialized recovery systems
  • Serial bloodwork and monitoring for muscle damage, dehydration, and systemic illness
  • Advanced imaging or repeat radiographs when needed
  • Management of concurrent dystocia-related complications such as severe trauma, metritis, retained membranes, or laminitis risk
  • Extended hospitalization and rehabilitation planning
Expected outcome: Guarded. Some mares recover with intensive support, but prolonged recumbency, worsening weakness, or severe associated injuries can make the outlook poor.
Consider: Provides the broadest support and monitoring, but requires substantial time, labor, and cost. Even with intensive care, not every mare will regain safe function.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Obturator Nerve Paralysis in Horses

Bring these questions to your vet appointment to get the most out of your visit.

  1. You can ask your vet whether this looks like an isolated obturator nerve injury or whether other nerves may also be involved.
  2. You can ask your vet what findings make fracture, hip luxation, or another orthopedic injury more or less likely.
  3. You can ask your vet whether your mare can be managed safely at home or should be referred to an equine hospital.
  4. You can ask your vet what type of footing, stall setup, and hindlimb support would reduce the risk of repeated slipping.
  5. You can ask your vet how long improvement usually takes in a case like your mare's and what milestones they want to see over the next 24 to 72 hours.
  6. You can ask your vet what postpartum complications they are also monitoring for, such as retained placenta, metritis, colic, or laminitis.
  7. You can ask your vet what medications they recommend for pain and inflammation and what side effects or monitoring are important.
  8. You can ask your vet at what point the prognosis becomes poor enough that a different care plan should be discussed.

How to Prevent Obturator Nerve Paralysis in Horses

Prevention centers on reducing dystocia and foaling trauma. Good breeding management matters. Matching stallion and mare size thoughtfully, monitoring mares with known foaling risks, and having a clear foaling plan can lower the chance of a prolonged or difficult delivery. Miniature horses and smaller mares carrying relatively large foals deserve especially close attention.

During foaling, timing is critical. Merck advises veterinary evaluation if the foal is not delivered within 30 minutes after rupture of the chorioallantois or if second-stage labor does not begin after more than 4 hours of obvious first-stage labor. Rapid recognition of a problem can shorten the period of nerve compression and reduce the need for forceful extraction.

Avoiding excessive traction is also important. If a delivery is not progressing normally, repeated pulling without correcting the foal's position can increase trauma to the mare. Your vet may recommend controlled vaginal delivery, referral, fetotomy, or cesarean section depending on the situation. The best preventive step is often getting skilled help early rather than trying harder for longer.

After foaling, watch the mare closely for weakness, slipping, pain, retained membranes, or abnormal behavior. Early postpartum examination is especially valuable after any hard birth. Prompt support can sometimes keep a mild nerve injury from becoming a much more serious down-mare emergency.

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