Last Updated on August 21, 2023 by Allison Price
This disorder does not have to end your horse’s performance career.
You don’t often think of “four-star event horse” when you think about spinal problems and skeletal disorders. But Meg Kepferle has a Thoroughbred gelding Anakin who is off-the track. Anakin is a terrifying condition that causes bony areas of the horse’s spine to touch or overlap. Many horses with kissing spines, like Anakin can have full-time performance careers. It’s a complicated disorder that requires proper management and treatment to keep these horses happy and healthy.
Anakin’s story is shared by Kepferle, a former groom for Sinead Halpin, who has her own training facility at Mountain View Farm, Long Valley, New Jersey. Weston Davis, DVM and DACVS, from Palm Beach Equine Clinic, Wellington, Florida provides an expert view on the disorder’s causes, treatment, and outcomes.
What are kissing spines?
Technically, kissing spines is known as interfering with or impinging the dorsal spinous process. The bony portion that sticks up from each vertebra is called the dorsal spineous process. The spinous processes should be evenly spaced so that the horse can comfortably move his back in a variety of anatomic positions. However, kissing spines can lead to multiple bony extensions touching, or even overlapping, in some cases.
This X-ray shows dorsal spinous process of a Dutch Warmblood mare aged 18 who was diagnosed with kissing her spines. The bony portion that sticks up from each vertebra is called the dorsal spineous process. The processes should be evenly spaced. However, if the spines are kissing, then two or more bony extensions can get too close to each other, touching, or even overlapping.
This can cause limitations in mobility and discomfort that can eventually lead to back soreness, performance issues, and even worse, pain. Kissing the spines is a leading cause of horseback pain. They can also cause additional problems such as bone cysts, sclerosis, thickening bone, or new bony deposits along the margins.
Dr. Davis says that kissing spines can occur theoretically anywhere in the thoracic and lumbar regions of the back. These are the areas of the spine with prominent dorsal spinous processes. He says that almost all cases of kissing spines will be found in the area from the bottom-slope to the withers, which is around vertebrae T6 through T18. This is where the saddle rests. It is not common to kiss spines in the lumbar area, or lower back.
Some horses may not show discomfort when they are seen to kiss their spines on radiographs. Dr. Davis says that many horses exhibit kissing spines only when they are asked for radiographs. He says that in these cases it is difficult to determine if the horse will have any problems later.
Anakin was already showing signs of tightness in his back. Anakin was very tight in his back. Kepferle stated that you could see the spasm. The muscles felt almost contracted, and looked tight. Dr. Davis says that horses should feel some flexibility in their muscles when they feel it. For horses like Anakin, who have symptoms, the reason for the pain is “a very tricky question.” There is no clear explanation as to why horses feel pain or why they are asymptomatic. Horses with minor impingement may be more painful than others.
He believes it is most likely due to a combination bone pain, i.e. the spinous processes affected touching and inflaming one another, as well activation of the local nerves in the region soft tissue.
Dr. Davis says that these horses eventually learn to brace their backs with the muscles of the back. This is basically a secondary muscle spasm, which can be very painful.
What causes kissing spines?
Experts believe that as high as 20% to 30% of horses are affected by kissing spines. It can affect any horse, of any breed, and any discipline. Dr. Davis says that horses with a long back are more likely to have problems, particularly if they have a swayed back. This combination can cause horses to lose their core strength and muscling, which can lead to serious problems. Inverted back conformation results in all dorsal spinous processes being closer together.
Kepferle agrees, noting Anakin’s long back and weak topline without stretching or strengthening exercises.
Dr. Davis found that horses who are involved in inversion of their toplines during athletic activity are more likely to develop symptoms. For example, barrel racers or jumpers who invert the back of their horses when they turn sharply or eventers who invert on landing. He also said that a heavy rider, when compared to the horse’s size, a poorly fitting saddle, and a rider who bounces around can all contribute to symptoms.
Dr. Davis says that asking for too much engagement or collection from a horse when they aren’t physically ready can lead to increased pain. Before attempting to injure the back with advanced athletic endeavors, horses should be well-muscled and mature.
Kepferle never asked Anakin to engage in a high level of conversation during any ride. She says, “It’s only now that the 11-year-old is strong enough to work on collection.” He’s ready to learn Advanced dressage. He wouldn’t have been able to do so much collection work if he had tried it earlier. It’s not possible to skip steps. That’s a huge, important thing.
The Symptoms
What are some signs that horses might be experiencing pain from kissing their spines? You can think of any sign that could indicate back pain.
Dr. Davis says that symptoms can vary greatly. “Some horses can be sensitive to touch, so people may feel a sensation when they brush the topline. Many of these horses experience spasms in the regional musculature and spinous processes.
He continues, “One of our most common things is intermittent, severe poor behavior.” Jumpers may jump after a fence, kick out, run away, or buck. A horse might become irritable and develop a negative attitude.
Dr. Davis says, “Watching them will show you that they travel with a stiff, stilted back, and that they carry themselves like a board.” Sometimes you can see this with a rider but other times you can see it free-willingly.
Another sign that your horse is not willing to bend in one direction, refuses to take one lead, drags a rear foot, refuses to accept the bit or has decreased range of motion could be fidgeting while grooming, nipping at the girth or bolting when you sit in the saddle. Sometimes, symptoms may appear suddenly even though they have been present for some time.
Anakin had been Anakin’s baseline since the day she bought him. This included a sore back and difficulty bending. Behavior issues didn’t arise. She recalls that he never said “no” to anything. “I never felt that anything was stopping him from doing the job that I wanted.”
Diagnoses of Kissing Spines
After purchasing Anakin, Kepferle spent the first year and half addressing his back problems with saddle fit, chiropractic care, and MagnaWave electromagnetic therapy. This treatment stimulates cell metabolism and increases blood circulation, while also reducing pain and inflammation.
After a thorough evaluation and lameness exam, your veterinarian will order radiographs to confirm that your horse is in pain. These will be taken from the side and show the distance between spinous processes. This will help determine if there is impingement.
Anakin’s topline started to improve but Kepferle noticed that he still had chronic back pain. “He was so calm, I knew that even if he showed mild discomfort, it was likely to be more severe than it appeared.”
Jan Henriksen DVM of B.W. was her vet. Furlong and Associates had been providing Anakin with regular care and were working with Kepferle to alleviate the horse’s back pain. They also assessed Kepferle’s fitness and riding and worked out how to make him more comfortable. They decided that it was time to have X-rays together.
Kepferle says, “It looked way more terrible than we expected.” “He touches in almost every vertebra on his back.”
Although Dr. Davis recognizes the importance of Xrays for diagnosing kissing spines, he also states that it is not the first step in assessing a horse suffering from a suspected case. Instead, Dr. Davis will evaluate the horse’s conformation, topline muscling and then move on to a thorough lameness exam. He says, “It is important to rule out any lameness that might be a part of the puzzle.”
He’ll also observe how a horse moves in a straight line, at trot, and canter around a circle. He will look out for signs of pain, muscle spasms or other abnormalities on the horse’s back and palpation.
Dr. Davis says, “For many horses, there will only be one behavior, so an under-saddle examination is important too.” Owners will often upload videos of their horses exhibiting problem behaviors, as it is difficult to replicate the behavior in the moment of the exam. Dr. Davis says, “Radiographs are an intuitive next step to rule out impingement in or outside of the spine once I am confident that the problem is to the back.” The vet will perform lateral spinal radiographs, which are X-rays taken on the side to show the distance between spinous processes.
Dr. Davis says, “If I find sites touching, overlapped, or close–anything suspect–then the following step is to block those sites.” The vet will apply a small amount local anesthetic to the affected area, effectively numbing it.
Dr. Davis says, “If the horse’s [symptomatic] behavior has been consistent or severe enough, I can create the situation that exacerbated it and, ideally see an improvement [with blocking].” It works in some horses. A subset of horses will partially respond. It is important to remember that many horses experience generalized or spasmodic back discomfort that may not respond to the small regional block.
A therapeutic trial might be an option if kissing spines is still the main suspect, but blocking doesn’t provide firm evidence. The vet will then attempt a conservative treatment, which is a local cortisone shot. Dr. Davis suggests stretching and core strengthening exercises for two to three weeks after the injection. Some can be done on the longe or in-hand but no rider for the first one to two week. This allows the affected area to heal and reduces inflammation.
Dr. Davis says that after the rest, the horse is put back to work to see if there are any signs of improvement. He also suggests that the horse may have been kissing his spines or back pain as a contributing factor to his problem.
If the horse does not show improvement after the therapeutic trial, the owner and veterinarian should consider whether the horse is in severe enough pain that medical treatments are not possible or if the cause is other than the horse’s own. Dr. Davis says that advanced diagnostics like ultrasound and scintigraphy [bone scanning] can be used to rule out other causes of back pain or provide additional evidence regarding the active nature of the kissing spines disease.
Medical Treatment
Some horses may only require a cortisone injection. Other horses may need to be adjusted to their exercise program. Some horses may require additional support treatment. The details will depend on each horse’s specific condition. These may include shockwave, MagnaWave and muscle relaxants.
Dr. Davis administers mesotherapy-style injections to a horse suffering from chronic back pain. A small amount of cortisone and B-12 are injected into the middle layer of skin using small needles. This helps reduce muscle spasms as well as hypersensitivity to local nerves.
Sometimes, the owner and vet may choose to give one or more of these treatments first before proceeding to injecting. Kepferle says that Anakin started to feel discomfort after the first of three treatments. This was unusual for a gelding, as he began to swap leads. Kepferle says, “It was almost as if, now that he understood we knew, he was asking us for help.”
After having tried many other non-invasive options, Kepferle decided to have a corticosteroid shot. This was in 2018. That was in 2018.
Physical Therapy
Kepferle did more than just administer the injection to improve Anakin’s condition. Instead, she built his training and conditioning program around stretching and core strengthening–building muscle over his topline and abdomen. She notes that it is important to recognize and then find ways to overcome physical limitations. This will help avoid frustrations which can lead to behavior problems.
Anakin now does slow and fast hill work. Kepferle points out that Anakin’s horses all do hill work and she increases the difficulty. She will, for example, start by walking up and down the hill. Then she will progress to trotting, and, if her horses are competing at Training level, to cantering uphill.
Anakin also includes a lot long and low work in the arena or on other good flat feet. He is encouraged to move forward in an extended frame, “over the back”, and reach for the connection.
An aquatred, an underwater treadmill, is also used by her. She also does a lot of hand stretching exercises that were taught to her by her veterinarian and equine chiropractor. A core strengthening program can include careful, thoughtful collection work.
Anakin uses an aquatred (or underwater treadmill) to train. This is only one part of a conditioning and training program Kepferle created to improve Anakin’s kissing spine condition.
Kepferle will skip under-saddle work once a week in favor of longeing. Pessoa (r. Lunging System), Lungie Bungie cords, and Equiband (r. System) are some of her aids. She explained that they all work together to get the horse to use their backs properly, rather than using the forehand or inverted spine.
Kepferle warns that everyone should educate themselves about the proper use of these systems before they are given to them. They can cause more harm than good when used incorrectly. It took Anakin months to get used to cantering along the longe. I tried to keep Anakin happy, confident, and forward-thinking.
Kepferle claims that Anakin’s Xrays were perfect and she would have continued with the same plan if Anakin had been healthy. This is due to the geldings’ long-backed conformation. This is a method Dr. Davis recommends to prevent horses that show X-ray evidence of kissing their spines, but no symptoms.
Surgical Treatment
Dr. Davis will only consider surgery if medical and/or physical therapy fails to improve the horse’s condition. He says that the surgery is not complicated or fails, but for a substantial portion of these horses, it’s possible to perform surgery if the owner has taken all the necessary precautions.
Dr. Davis describes a “slam-dunk” candidate for surgery. The horse must have strong clinical symptoms, evidence that there is impingement or overlapping spinous processes, and clearly identify the area of pain on the clinical exam. The horse should also be able to respond positively to nerve blocking.
Dr. Davis performs an osteotomy, which is a procedure in which the spinous process are reshaped under general anesthesia. This procedure is more common when the horse is standing and with local anesthesia.
Courtesy of Dr. Weston Davis
Dr. Davis says that surgical procedures for kissing spines disease are very successful. Numerous studies have shown that 72 to 95 percent horses are able to return to work after having surgery.
Three primary surgeries are available to treat kissing spines.
Interspinous nerve desmotomy. This procedure involves the use of ultrasound or X-ray guidance to cut the ligament between the spinous processes affected. Dr. Davis says that this procedure is the most common. It’s also minimally invasive, and can be done standing. He says that there is a good chance of success. However, this procedure is not recommended for horses with mild impingement. He says that it may be difficult or impossible to reach the surgical instrument between the spinous processes in more severe cases to cut the ligament. In these cases, cutting the ligament might not be beneficial.
Osteoplasty. The vet will reshape the spinous processes and shave off some bone during this procedure. Dr. Davis explains that if the horse has bone on-bone or overlapping bones, we can remove a small section of bone to increase the space. He notes that the ISLD procedure can be performed simultaneously by the vet. This surgery is more complicated and requires a longer recovery time.
Ostectomy. Dr. Davis explains that this is essentially an osteoplasty with steroids. This surgery involves more bone removal. He says, “Instead of simply widening the space we take a bone see and remove a significant portion [of the spinous process] or almost all of it.”
Sometimes, the vet may perform multiple procedures in one surgery. Dr. Davis explains that if a horse has four spots, he may perform osteoplasty to widen one spot and then do an ostectomy on the other two. It all depends on how badly impinging, misshapen, or unhealthy the bone appears.
This and the next image show before and after images of an osteoplasty. It is a procedure in which the veterinarian changes the shape of the spinous processes. The vet does this by removing some bone to increase the space.
Continued Care
After any surgery to kiss the spines, Dr. Davis will place the horse on stall rest for a period of two weeks until the sutures are removed and the incision heals. After that, Dr. Davis will put the horse on stall rest for two weeks until the sutures are out and the incision is healed. Then, he will start stretching for the horse for two more weeks. He says that he may do physical therapy for mild cases and under-saddle work in 30 days if they are not suffering from severe injuries. They may only be receiving physical therapy for 60-90 days if they are more severe.
He says that stretches and physical therapy are still important for horses’ athletic careers.
Kepferle is a perfect example of this. She says, “Training-wise I’ve always prioritized his health and body comfort over all else. And then everything else has been very simple.”
Anakin still does MagnaWave treatments and strength training as part of his weekly routine. Meg also follows Anakin’s galloping one day with a day of work on the longeing equipment. She usually jumps him only once per week. “If I jump more than once, the second session is mainly about strength training with small jumps and getting his back to work properly. She adds that she gallopers as often as necessary, but not more.
Kepferle points out that Anakin had very little topline muscling when she bought him. She says that Anakin looks great and has a great topline. “The better the topline is, the more it can support the spinal process so they don’t touch as often and [the horse] can use his back properly.”
Anakin’s condition is her favorite subject of concern. She said that the best advice she received was to “ride the horse like he doesn’t have kissing spines.” She explains that you should work them forward and through to build muscle. “[Anakin] does not have the natural flexibility of a horse. He would never be stronger if I didn’t make him bend and do more difficult things.
She also monitors his soreness and adjusts his schedule as necessary, such as skipping a gallop, or giving him another day off. She notes that it is important for everyone to learn how to properly care for their horses and make a habit of checking his back before and after each ride. Kepferle administered another injection to Anakin when he started feeling sore after gallops during the spring 2020.
Kepferle cried for two days when she learned of Anakin’s condition. She says that he is now thriving. He was in Prelim getting ready for Intermediate when we learned about his kissing spines. He’s now an Advanced horse.” Anakin finished the Fair Hill CCI ****-L October 2019, and was ready to go up to the five star level.
Look Beyond Kissing Spines
According to Dr. Davis and Kepferle the bottom line is that a diagnosis of kissing spines shouldn’t cause fear in horse owners or buyers. Dr. Davis says, “If we see kissing spinals on a prepurchase exam it doesn’t make us that nervous.” Most of these horses are medically manageable. Most horses will recover well if you go the surgical route.
Dr. Davis states that few horses will need to retire due to kissing spines, “if we aren’t restricted by advanced age, finances, etc.” This condition is common in horses that were retired and pasture turnout is the best result. The quality of their lives is excellent.
Meg Kepferle was devastated when Anakin, her eventer, began to kiss spines. However, with proper treatment and management, he has progressed from Preliminary to the Four-Star level.
Amy K. Dragoo/AIMMEDIA
Kepferle met with many top-level riders and has also worked with horses affected by Anakin’s kissing spines since discovering them. She says that while there are cases in which the horse can’t do certain things, there are many others where the horse can continue to have a successful career. That gave me hope. This is a sad fact. It is totally manageable.
Kepferle hopes to share her story and encourage others to do the same. She hopes to “help change the culture and attitude surrounding this condition and give a chance to some great horses who might otherwise be overlooked.”
