The term “kissing spines” often causes a great deal of confusion and concern among horse owners. A few years ago, a diagnosis of kissing spines was usually considered the end of a horse’s active career. Today, we know more about this back condition—but still not everything.

Kissing vertebrae?

First, the name. “Kissing spines” literally means “kissing vertebrae,” which suggests that the vertebrae themselves are too close together. This is not the case. The condition concerns the dorsal spinous processes of the vertebrae. In humans these are very short, but in horses they are much longer. You can feel them when you run your hand along the middle of your horse’s back. The small bumps you feel are the tips of these processes; the vertebral bodies themselves lie much deeper within the body. The long spinous processes can sometimes be positioned very close together, allowing them to touch—sometimes permanently, sometimes only during certain movements, such as when the horse hollows its back.

What happens in kissing spines?

When the spinous processes touch (occasionally or constantly), this can cause irritation of the bone. This may lead to inflammation, pain, and eventually bone changes. The attachment points of the ligaments surrounding the spinous processes can also become irritated. There is considerable debate about the exact cause of kissing spines. The horse’s conformation plays a major role, and incorrect training or a poorly fitting saddle can worsen the situation. However, some horses that have never been ridden already have kissing spines, indicating that natural conformation is very important. The quality of bone development during a horse’s youth also has a significant influence on how the skeleton ultimately develops. This applies not only to kissing spines, but also to conditions such as OCD. A healthy skeleton starts with a good upbringing, including high-quality nutrition with sufficient minerals (especially silicon) and, above all, plenty of free movement for the growing horse.

Kissing spines present but no problem?

There is a huge variety in skeletal conformation among horses. Mild forms of kissing spines are also very commonly seen on X-rays. This often alarms horse owners, but it is important to note the difference between what is visible on an image and what it means in practice. Veterinarians refer to this as “clinical relevance.” The first step is identifying kissing spines on an X-ray. The next step is determining whether these findings actually cause clinical signs. This is often not the case, or only under certain conditions. Not all changes to the spinous processes are painful or lead to back problems. In many cases, further investigation is needed to rule out other issues, such as lameness in the limbs. Scientific research has shown that back pain is more common when radiographic changes of the spinous processes are more pronounced. Additionally, horses with abnormal spinous processes are more likely to experience back pain when there is also a (subtle) lameness, osteoarthritis of the facet joints, or osteoarthritis of the sacroiliac joint. Very often, a combination of factors is involved. A horse with leg pain will alter its movement to avoid discomfort, which can in turn lead to back problems. If, in such a case, only X-rays of the back are taken and mild kissing spines are found, these are not the original cause of the problem and focusing solely on the back will not resolve the issue.

Treatment of back pain in kissing spines

A horse suffering from kissing spines will show pain during certain movements, handling, or training situations. This pain can be subtle and difficult to detect. The horse may show discomfort during saddling, bending, or striking off into canter. Back problems are often noticeable because the horse does not want to stretch and soften into the contact. Signs of back pain can also appear during grooming. Resistance, bucking, or bolting may also indicate back pain. If your horse has back pain and kissing spines are visible on X-rays, other problems and sources of lameness should first be ruled out. Treatment can then begin, usually starting with pain management. Your veterinarian may inject anti-inflammatory medication locally into the back, and there are also infusions that stimulate bone remodeling. Mesotherapy is often recommended as well, as it helps reduce muscle tension around the back and alleviates pain. Once the pain has decreased, movement becomes essential. Your horse’s back needs to learn to move correctly again, and compensatory movement patterns that developed to avoid pain must be addressed. Specialists such as physiotherapists or chiropractors can be very helpful in this process. Ensure that your horse has a well-fitting saddle and a balanced rider who is not too heavy. Your horse must learn to engage its abdominal muscles, which lifts the back and increases the space between the spinous processes during movement so they no longer touch. Your veterinarian or physiotherapist can also prescribe stretching exercises for your horse. Always monitor for other potential lameness issues to prevent renewed compensation.

Supporting a horse with kissing spines

Silicon is a very important mineral for the development of bones as well as all structures that hold the skeleton together, such as ligaments and tendons. Easily absorbable, hydrolyzed silicon can be added to your horse’s feed as a supplement. Silicon stimulates the body’s natural production of glucosamine and works from the outside in. To have an effect on the bones themselves, this supplement should be given for at least three to six months. Once your horse is free from back pain and you can begin rebuilding exercise, it is also important to stimulate muscle development. The muscles should ultimately take over much of the load-bearing function, reducing strain on the skeleton. Good muscle development starts with proper training and the right building blocks. Amino acids, magnesium, and vitamin E are particularly important. If your horse occasionally still experiences mild pain, you may consider supporting it with an extract from the clove plant, which has pain-relieving and anti-inflammatory properties.