Dorsal spinous processes (DSPs) are the bony projections at the top of the horse’s vertebrae. When those projections touch (impinge) or overlap (override), this is referred to as “kissing spines.”  The area of the back where the condition is most often diagnosed is between thoracic vertebrae T13 and 18—directly under where a rider sits in the saddle.

A horse with four sites of impingement with bone remodeling, suspected to be causing the horse’s pain under saddle. Photo by Alan Nixon

Signs a Horse May Have Kissing Spines Include:

◆ Obvious discomfort with pressure on back

◆ Loss of muscling across topline

◆ Change in behavior (tail swishing is common)

◆ “Hollowed out” back when ridden

◆ Resistance to transitions between gaits

◆ Asymmetric, uneven gaits

◆ Difficulty picking up correct lead or maintaining canter

Obvious discomfort from pressure on the back is one possible indicator of kissing spines. Photo by Talitha/Adobe Stock

A Diagnosis is Not Always Career-Ending

Although radiographs may look alarming, the presence of kissing spines isn’t necessarily the kiss of death for a horse’s athletic career. In fact, many horses whose X-rays reveal the condition have no clinical signs and compete at top levels.

Researchers at the University of California-Davis recently studied groups of horses that compete successfully in high-level show jumping and racing over fences. X-rays of these horses’ backs showed that kissing spines was very common, yet there was no correlation with poor performance. In fact, horses with the worse radiographic evidence of kissing spines often had better jumping scores and racing accomplishments.

“It’s incredibly common to have horses show abnormalities of their backs on X-rays, but our clinical experience and research studies show that kissing spines doesn’t necessarily mean a horse has back pain or poor performance,” says Sarah le Jeune, DVM, DACVS, DACVSMR, CVA, of UC Davis, who regularly works with horses with the condition. Le Jeune specializes in equine integrative sports medicine and rehabilitation, and she is also a surgeon.

“Kissing spines is getting blamed clinically for a lot of things, so you have to rule out other problems,” says le Jeune. “I rarely see horses with primary back pain; it’s usually secondary to lameness, poor saddle fit, or unbalanced riding.” Her goal is getting to the root of the problem and fixing it.

“Back pain and lameness are highly correlated and hard to separate,” she notes. “If there’s an underlying lameness, once the horse is better, he starts using his back better.”

Not Just X-Rays

Radiographs alone should never be the sole evidence for a diagnosis of kissing spines. It’s believed that almost 35 percent of horses show evidence of the condition on X-rays, but they may have no clinical signs.

“Typically, when you X-ray horses’ backs, they’re sedated, and their posture is passive,” says le Jeune. “They’re not engaging their abdominal muscles and are kind of slouching.”

This doesn’t reflect the horse in movement with an engaged hind end and lifted back.

“It’s not uncommon to see kissing spines on X-rays, but the sedated, standing horse is not the same as the dynamic horse in motion,” she adds.

The condition has even been seen on X-rays of foals’ backs, which proves it’s not related to being ridden.

When conducting a pre-purchase exam, le Jeune won’t necessarily “red flag” a horse with kissing spines on the X-rays if he moves well and has no back pain, but she lets the buyer know it could become a problem if the rider is not able to ride the horse with an engaged and lifted back.

Because the condition is so frequently seen on X-rays, an accurate diagnosis of kissing spines must include clinical correlation.

“Horses with clinical kissing spines have obvious pain upon palpation and riding,” says le Jeune. “The diagnosis has to be confirmed with physical examination and palpation of the back, including a thorough lameness evaluation, neurological evaluation, and saddle fit evaluation.”

She also recommends evaluation of the horse being ridden by a veterinarian well-versed in sports medicine.

Why Horses Develop Kissing Spines

There is no single answer as to why some horses develop kissing spines. Likely, the condition is the result of multiple factors, including breed predisposition and genetics, poor saddle fit, unbalanced riding, and lack of training that allows the horse to not engage his core.

At times, conformation is to blame. A horse that genuinely has bad posture related to conformation may be physically incapable of using his body properly for high-level performance.

“Saddle fit is a huge problem,” adds le Jeune. “The saddle has to fit the rider, not just the horse. Most owners want to do what’s right by their horses. It might mean getting a different saddle or becoming a more balanced rider. It takes self-awareness and willingness to address the root problem.”

Different Approaches to Kissing Spines

When all other issues have been ruled out and a horse has a definitive diagnosis of kissing spines, there are different approaches to addressing the condition:

◆ Medical treatment

◆ Postural rehabilitation

◆ Surgery

Medical treatment may involve muscle relaxants, anti-inflammatory medication, and steroid injections between the offending DSPs. Some horses with the condition may benefit from steroid injections a couple times per year to reduce inflammation in the affected area(s) of the back.

Le Jeune has also seen improvement using shockwave therapy, chiropractic adjustment and acupuncture. Although these therapies can be very helpful, the horse must still have a strong back and move correctly, which is why postural rehabilitation is key.

Secondary to postural rehab, Le Jeune has also seen improvement using shockwave therapy, chiropractic adjustment and acupuncture. Photo by RD-Fotografie/Adobe Stock

Postural rehabilitation involves exercises that engage core muscles and strengthen the muscles that support the spinal column. The goal of postural rehabilitation is getting the horse to use his back properly, by tucking his pelvis and lifting the back.

“Postural rehab can include resistance bands like the Equiband Pro System, the ProSix, or the Pessoa Lungeing System,” says le Jeune. “All of this is done without a rider and rehab can take two to three months.”

Postural rehabilitation, which might include the Pessoa longeing system, involves exercise that engages core muscles and strengthens the muscles that support the spinal column. Photo by matilda553/Adobe Stock

When owners choose surgery for severe cases, there are two options. The most common surgery, known as interspinous ligament desmotomy (ISLD), involves snipping the ligament(s) holding those segments of the spine together.

“A branch of the spinal nerves in that region are cut during the surgery, so it’s like a neurectomy, meaning the horse won’t be able to feel that area of the back,” explains le Jeune, adding that this may possibly make the back less stable.

A more radical and invasive surgery, known as ostectomy, actually cuts away the top of the dorsal spinous processes that are touching.

Post-operative image of the same horse following cranial wedge ostectomy of the four sites. Photo by Alan Nixon

Some surgeons are combining ISLD surgery with a process known as “bone shaving,” which removes smaller bone sections and is less radical than an ostectomy.

While surgery for kissing spines is common, le Jeune believes it’s only warranted when the diagnosis is absolute and there are no better treatment options. In practice, she has found that postural rehabilitation is often a more successful approach.

When an owner chooses this option, it’s important to work with an expert who is experienced in rehabilitation, which is usually a veterinarian who is board certified in sports medicine, so don’t hesitate to seek out a specialist.

Return to Work

Most horses with clinical signs are able to return to work after treatment, but owners should be aware that rehab takes time and commitment on their part.

“As long as you’ve ruled out everything else, it’s very rare that postural rehab doesn’t work,” says le Jeune. “But correct riding is crucial. You need to have a skilled rider once the back is strengthened in order to keep the horse engaged and using his back properly.”

Correct riding is crucial when returning to work. A strong equine back and skilled rider is needed to keep the horse engaged and using his back properly. Photo by RD-Fotografie/Adobe Stock

As an avid rider herself, le Jeune understands the condition from this perspective.

“Once the horse develops more back muscling, he’ll get wider, so you may need to adjust or change saddles,” she adds, noting that regular saddle re-evaluation is essential, with adjustment as needed.

Key Takeaway

Although kissing spines has become a common diagnosis in performance horses, le Jeune emphasizes that the condition shouldn’t be the go-to explanation for poor performance or back pain.

She encourages owners and veterinarians to definitively rule out any other problems, particularly lameness, before confirming a diagnosis of kissing spines and pursuing treatment.

She adds that choice of treatment should always focus on what’s right for the horse long term—not necessarily the option that brings about the fastest results.

This article about kissing spines in horses appeared in the January/February 2025 issue of Horse Illustrated magazine. Click here to subscribe!

The post An Overview of Kissing Spines in Horses appeared first on Horse Illustrated Magazine.

A stiff, hollow way of moving under saddle or head-tossing can be indicators of kissing spine. Photo by Fotokostic/Shutterstock

Also Read: Expert’s Advice on Kissing Spine

The expression of kissing spine is often not clear cut; the horse may shift his weight when groomed over his back or be reluctant to be saddled. He may not stand to be mounted or may bolt when the rider places weight in the saddle. The horse may buck, rear or kick out repeatedly.

A horse with kissing spine may shift his weight when groomed over his back or be reluctant to be saddled. Although these issues can be caused by other problems, kissing spine shouldn’t be ruled out without a veterinary exam. Photo by Amy Dragoo

Less obvious signs can be a horse that is stiff under saddle or one that is consistently hollow or tosses his head. He may be reluctant to go forward or have trouble picking up the correct lead or maintaining a true three-beat canter under saddle. While many of these issues can be caused by other problems, kissing spine shouldn’t be ruled out without a veterinary investigation.

A Sweet Name for a Sour Problem

True to its name, kissing spine occurs when the bony projections (called dorsal spinous processes, or DSPs) on a horse’s vertebrae rub or impinge on each other, causing pain and changes in the bones and ligaments that attach to them, explains Liberty Getman, DVM, an associate surgeon at Tennessee Equine Hospital. Getman graduated from the University of Florida before completing a residency at the University of Pennsylvania; she is specifically interested in lameness and orthopedic surgery.

Kissing spine is suspected when a horse shows significant, consistent pain when light pressure is placed on the lumbar and lower thoracic spine, Getman explains. The condition is often most painful when the horse is wearing a saddle; the afflicted horse is often sound but displays behavioral problems when ridden. The condition can greatly affect a horse’s performance.

Kissing spine is suspected when a horse shows significant, consistent pain when light pressure is placed on the lumbar and lower thoracic spine. Photo by Amy Dragoo

Some cases are so severe that the DSPs can overlap by as much as 50 percent, says Lauren Luedke, DVM, Dipl. ACVS-LA, a Colorado State University graduate who completed her residency at Cornell University before becoming a surgeon at Manor Equine Hospital in Maryland.

Interestingly, horses diagnosed with kissing spine exhibit varying degrees of pain—and the degree of abnormality does not always dictate the level of pain, says Luedke.

“For example, there are some horses with severe changes and minimal back pain and some horses with mild radiographic changes with marked back pain,” she explains.

In what would be considered a “normal” horse’s spine, the dorsal spinous processes (DSPs) don’t rub together or overlap each other. Photo by Willierossin/Shutterstock

Kissing spine can be diagnosed using a combination of methods, but each will begin with a clinical exam. Based on exam results, radiographs can be used to confirm findings as evident by impingement and bone remodeling of one or more of the dorsal spinous processes, says Luedke. In more complex cases, nuclear scintigraphy (bone scans) can be useful in detecting active bone remodeling, indicating that DSP impingement is a primary problem.

A horse with four sites of impingement; the first site (*) is suspected to be impinging under saddle, followed by two sites with obvious impingement and bone remodeling (arrows), and a fourth site with overriding DSPs with bone remodeling evident (arrow head). Photo by Alan Nixon

Post-operative image of the same horse following cranial wedge ostectomy of the four sites. Photo by Alan Nixon

Blocking the sites of impingement with carbocaine (a numbing agent) may be useful. However, because some horses can have radiographic changes (visible on X-ray) without clinical signs, Luedke stresses that it’s important to analyze findings collectively to arrive at a diagnosis.

Kissing Spine Prognosis and Treatments

The prognosis for horses with kissing spine is fair to good with appropriate management, according to Luedke.

Getman agrees.

“It’s important to remember that horses with kissing spine have an excellent prognosis for life, and that the prognosis can be good-to-excellent for athletic performance,” she says. “The severity of the disease and how many sites are impinging influence prognosis.”

Treatment of the condition can range from back injections to surgical removal of the bone that is impinging and causing pain. Luedke says that treatment often begins with the administration of anti-inflammatories and muscle relaxers, and a steroid injection between the impinged DSPs. Injections are not a one-and-done solution, however.

“The hope is that the injections last for six months to a year, but in more severe cases, [the injections] may only last a couple months,” says Luedke.

Getman also often recommends chiropractic adjustment, acupuncture and mesotherapy to horses in her care that are affected by kissing spine. Mesotherapy involves injecting small amounts of compounds into the middle layer of skin using very fine needles; it’s often used for pain management.

Dr. Liberty Getman recommends chiropractic and acupuncture treatments first after a diagnosis of kissing spine is determined. Photo by Amy Dragoo

If medical therapies are unsuccessful, surgery is an option. The more conservative surgery is known as an interspinous ligament desmotomy, or “keyhole” surgery. This minimally invasive procedure cuts the ligament that connects the two affected spinous processes to each other, explains Luedke, and can be done in multiple areas. This surgery allows more room between the DSPs and likely transects the nerve to eliminate pain.

A more invasive surgical option is a cranial wedge ostectomy, which removes the impinged bone and requires more extensive incisions and rehabilitation. The type of surgery pursued is often dictated by the severity of disease: in cases where the DSPs are overlapping, cranial wedge ostectomy is the preferred surgery.

Though horses affected by kissing spine experience the most pain when they are under saddle, most can have athletic careers if their pain can be managed, says Luedke.

“Some horses with explosive behavior may be too dangerous to ride,” even after their kissing spine issue is resolved, she notes. She says that the earlier pain a horse experiences from kissing spine is managed, the less likely he is to learn the explosive behavior associated with the back pain.

Luedke concurs.

“My experience so far is that horses with DSP impingement requiring surgery have done very well post-operatively,” she says.

She adds that there is one piece of the kissing spine puzzle that has not yet been tested.

“We don’t know yet know what happens to these horses 10 years from now,” says Luedke. “Is there any recurrence of disease, or can it occur at other locations? Or do the horses continue to do well because we have taken away the pain component, allowing them to use their back properly and maintain [muscle] strength?”

A Note on Rehabilitation

Kirsten Johnson, owner of Kentucky Equine Sports Medicine and Rehabilitation Center (KESMARC) in Versailles, Ky, which offers multiple treatments for a variety of conditions from which a horse may be recuperating.

These include a hyperbaric chamber, a pool, an underwater treadmill, and a cold saltwater spa, among others. Each of these has its place in the rehabilitation of various injuries, ailments, and surgeries, but Johnson has had extremely good results in horses suffering from kissing spine using a combination of treatments.

“I’ve had success with horses with very poor prognoses with doing a good [chiropractic] adjustment, saddle fit and back-strengthening exercises,” she says. “I’ve had horses that were going to be euthanized go back to lead quality, productive lives.”

One often overlooked facet of kissing spine pain management is saddle fit, according to Johnson. Also, compensatory pain is a concern.

“Once the horse starts hurting, other things go wrong,” she says. “Rehabilitation is focused on not only retraining the body, but also on hopefully making improvements there in terms of strengthening and lifting the back. You also have to focus on retraining the brain—and doing it safely,” she says of horses that may have developed dangerous habits resulting from perpetual pain.

The water does a very good job of letting horses reap the benefits of it use while forgetting everything that hurts, she notes. Whether the horse goes on the underwater treadmill or swims is dependent on the horse, his age and his discipline, she says. For horses that come to KESMARC for rehab for kissing spine, Johnson says she often sees marked results in 90 days.

Ninety days of swimming or underwater treadmill therapy can yield great results for horses with kissing spine. Photo by Kelly vanDellen/Shutterstock

Though kissing spine may seem like a death knell for a horse’s athletic career, it often is not. A veterinarian focused on a correct diagnosis and treatment for the individual horse is key, as is a well-defined, strategic plan to bring the horse back into work.

This article about kissing spine appeared in the April 2022 issue of Horse Illustrated magazine. Click here to subscribe!

The post Conquering Kissing Spine appeared first on Horse Illustrated Magazine.