Kissing Spines or Poor Saddle Fit? The Misdiagnosed Connection

Kissing Spines Diagnosis X-Ray

Kissing spines, or overriding dorsal spinous processes (ORDSP), occur when the bony projections atop the vertebrae (dorsal spinous processes) come into contact or overlap, potentially leading to back pain and compromised performance in horses. While the exact cause of kissing spines remains uncertain, evidence suggests that improper saddle fit can be a significant contributing factor.

 Kissing Spines are over-diagnosed because of the prevalence of poor saddle fit.

When the horse carries their spine and back in an inverted posture, it pushes the neck vertebrae down and forward, dropping the back. When the back drops, the spine hyper-extends downwards, causing gaps at the base of the vertebrae and touching or overlapping at the top of the vertebrae. This causes nerve impingement and pain. Despite this, many horses are diagnosed with kissing spines without a thorough evaluation of the role their tack and posture play in creating these conditions.

Tree angle too wide causing tightness and pressure on accessory nerve.

 A saddle with an excessively wide tree angle can exert undue pressure on the horse's withers, leading to discomfort and muscle tension. This pressure may cause the horse to hollow its back—a posture where the spine drops and the head raises—to alleviate the discomfort. Maintaining this hollowed position over time can decrease the space between the dorsal spinous processes, increasing the risk of developing kissing spines.

Conversely, a saddle with a gullet channel that is too narrow can compress the muscles adjacent to the spine, particularly the multifidus muscle, which plays a crucial role in stabilizing the vertebrae. Such compression restricts the spine's natural movement and flexibility, potentially leading to muscle damage and further contributing to the conditions that precipitate kissing spines.

The UC Davis Center for Equine Health emphasizes that kissing spines are likely acquired, and can result from, factors such as poor saddle fit and improper training techniques. These issues can cause the horse to carry itself with a hollow back, failing to engage its core muscles, thereby exacerbating the problem.

Multifidous Muscle

Pain radiating from common saddle fit OR kissing spines.

A case in point is a 7-year-old Thoroughbred gelding that was diagnosed with kissing spines after he started bolting and bucking after fences. This horse was a client of mine, and while I worked on his dressage saddle, his jumping saddle did not have any adjustability and therefore could not be properly fitted. I had the owners send me pictures of the horse and the X-rays the vet had reviewed. After analyzing them I decided to try something unconventional. I wanted to answer all the possible questions before the family invested in expensive surgery or considered giving up on the horse.

I asked if he ever exhibited these behaviors in his dressage saddle. The answer was no. Then I suggested they try something different—ride him over a full jump course, even with small fences, in his dressage saddle. They conducted the experiment and he showed no bucking or bolting in his dressage saddle. This was a significant clue.

Following this I recommended chiropractic care because he was extremely compressed at the base of the withers and neck. The before-and-after pictures from the chiropractic adjustment were astonishing. Before the adjustment his withers were level with his croup; afterward his withers were higher than the croup. He had been so compressed that he grew over an inch from a single adjustment.

Before and After Initial Chiropractic Adjustment

I then sent them a few saddles to try. Once we found one that both he and the owner liked, the bucking, bolting, and back pain completely disappeared. Two years later, he continues to receive regular saddle fittings and has had zero behavior issues under saddle.

Pliance Horse Saddle System showing pressure on the wither upon landing after a fence.

Research using the Pliance® horse saddle system has further highlighted the impact of saddle pressure on back pain. The highest-pressure readings during landing from a jump are not on the horse’s shoulder, as many assume, but rather on the wither under the stirrup bar. This excessive pressure can contribute to nerve compression, including irritation of the accessory nerve, which runs along the neck and into the shoulder region. When this nerve is impacted, it can lead to muscle spasm, tension, and pain that mimics symptoms of kissing spines.

The Accessory Nerve Location in Wither

When a horse is treated for Kissing Spine as if it is a genetic or conformational issue without addressing the contribution of the tack, it is a waste of time and money. On top of this, when a horse goes through the expensive, painful, and lengthy process of ORDSP surgery and then the same equipment is put back on them, the owner is often left wondering why the painful back and poor behavior persist. Is this a failed surgery, or is it that the vertebrae were never the problem but in fact the symptom of poorly fitted equipment? Without correcting the root cause—poor saddle fit—the cycle of pain and dysfunction continues.

 Given the overlap in symptoms between kissing spines and issues arising from poor saddle fit—such as back pain, behavioral changes, and reduced performance—it’s crucial to conduct a thorough evaluation before arriving at a diagnosis. Assessing saddle fit should be a primary step when a horse exhibits signs of back discomfort. Addressing saddle fit issues promptly can prevent the development or progression of kissing spines, ensuring the horse’s comfort and performance are maintained.

In conclusion, while kissing spines can have multiple origins, improper saddle fit is a significant and often preventable contributor. Regular saddle fit assessments, appropriate training practices, and bodywork or chiropractic care are essential in maintaining equine back health and preventing or treating conditions like kissing spines. Owners should be proactive in evaluating saddle fit to ensure their horse’s long-term comfort and soundness.