16 Apr

Equine Spay: Taming the “Nightmare”

My mare Fiddle was way beyond mareish. Her heat cycles made her uncomfortable, unhappy, and almost dangerous, especially in springtime.  Her nickname at the barn was “The Dragon,” and it was well-deserved.

What can you do with a “nightmare” who pins her ears, humps her back, and kicks out at anything (or anyone) who comes close?


Breeding is commonly suggested for mares who have a rough cycle.  The hormone boost from pregnancy makes many (but not all) mares happy and placid.  And at the end of a pregnancy, you get a cute little foal! 

This was not a good option for us. Supporting a pregnancy and raising a foal is an expensive prospect, and it’s possible that a daughter of a rough-cycling mare will inherit rough cycles herself.  And, of course, a mare may return to her old behavior once the foal is weaned.

Herbal supplements:

Herbal supplements like raspberry leaf (sold as Mare Magic) can help with tension and grumpiness for many mares. Raspberry leaf did help Fiddle’s tension but didn’t fix the entire issue.

Marble insertion:

Marble insertion is an experimental technique that helps some mares.  After a thorough reproductive exam, the vet inserted a marble into Fiddle’s feminine regions. Marble insertion suppresses estrus in about 50% of mares.  My horse was one of the other 50%.


Regumate works to suppress many heat cycle symptoms and is a good short-term option for rough-cycling mares needed for breeding.  Fiddle received Regumate for two years, and it helped quite a lot.  However, we needed a long-term answer.

Equine spay:

Equine spay is the solution that finally worked for us.  In April 2012, I took my mare for ovariectomy: an equine spay.

The process:

Spaying can be done under local or general anesthesia and by using a vaginal, flank, or ventral incision. Each method has a different cost and a varied set of risks, and some approaches are better than others for removing enlarged or diseased ovaries.

In Fiddle’s case, we opted for a standing surgery with flank incisions.  The laparoscopic took about 90 minutes.

On examination, one of her ovaries was deemed “mostly normal.”  The other had some cysts—not large enough to alarm the vet prior to surgery, but definitely large enough to cause chronic pain.

Fiddle returned home two days after surgery, and we confined her to a stall for about ten days, with frequent breaks of hand-grazing in the sunshine.  She is a calm horse, so we didn’t need additional sedation, although the vet made some available. 

Gradually, she returned to normal pasture turnout—in small areas at first, and then to increasingly large spaces. 

Seventeen days after surgery, I rode my horse lightly on trails.  A working endurance athlete prior to the surgery, Fiddle was still very fit after time off. Our early rides post-surgery were low speed and short duration.  Over the following weeks, I increased either speed or distance in each workout—not both on the same day.

Eleven weeks after surgery, with veterinary approval, we entered and completed a one-day fifty-mile endurance ride earning good scores through the entire course.  Fiddle competed in long-distance rides for an additional 5 years before retirement and was named “Endurance Standardbred of the Year” in 2015. She is still an active trail and dressage mount.

Spay surgery isn’t cheap, and it isn’t completely free of risk.  Spaying will not fix problems caused by bad training, poor nutrition, inadequate dental or farrier work, or a too-stressful living situation.  But for Fiddle and me, spaying was the best option available.

Years later, Fiddle is still a “dragon”:  she is a big, strong, opinionated athlete.  However, she is now “the same dragon every day.”  Her moods and her comfort are no longer at the mercy of hormone fluctuations.  She doesn’t guard her back anymore, and she spends energy moving forward instead of coping with pain.  She is quieter, she is kinder, and she is perceptibly happier in the pasture and under saddle.

A friend cringed at the price of surgery, saying that for the cost, I could have gotten a really good horse without the hormone problem.  I replied that for the cost, that’s exactly what I got:  it just happened to be the really good horse who already lives in my barn.

Fiddle at mile 60, Renegade Rendezvous.  Photo by Monica Bretherton, used with permission.

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