Kissing Spines in Horses: Symptoms, Diagnosis, and Treatment

Kissing spines in horses - Everything you need to know

Kissing spines, or 'kissing spinous processes,' refers to a spinal disease in horses that is being diagnosed with increasing frequency. This condition occurs when the spinous processes of the vertebrae gradually move closer together until they eventually touch. In severe cases, the vertebrae may painfully rub against each other, sometimes even crossing or overlapping. This often leads to inflammation between the vertebrae and the formation of bony protrusions. Early diagnosis is essential to prevent the progression of the disease and spare the horse from severe pain. As a horse owner, it is crucial to understand the causes of kissing spines, recognize its typical symptoms, and know how to respond if your horse is affected.

What is kissing spines in horses?

The term 'kissing spinous processes' directly reflects the underlying issue. The forward tilt of the first 14 thoracic vertebrae and the backward tilt of the following vertebrae cause significant compression between thoracic vertebrae 10-17, especially under the rider's weight. This compression can lead to the development of kissing spines.

Thoracic interspinal syndrome, often referred to as kissing spine syndrome, is classified into three degrees of severity, independent of clinical symptoms. This condition can develop even in horses that are not ridden. The syndrome causes bruising of the ligaments in affected areas, which may initially result in microtraumas. Over time, these microtraumas can lead to bony growths on the transverse and spinous processes, potentially causing the vertebrae to overlap, a condition known as 'overriding.' 

Symptoms of kissing spines in horses

Interpreting symptoms can be challenging. The condition often begins with reduced performance, which experienced horse owners may not initially perceive as serious. However, an important indicator is pressure pain in the affected areas of the spine. Additional symptoms that may arise include:

• Sensitivity when brushing/palpating the back
• Discomfort or resistance when mounting or starting
• Reduced muscle development along the back
• Behavioral issues related to the saddle and/or girth
• Lack of motivation to work
• Irregularities in movement (e.g., "clock errors")
• Crooked tail
• Problems with rideability
• Lack of forward momentum
• Limited activity of the hindquarters
• Inability to jump with an affected back
• Refuse before the jump
• Avoidance behaviors, such as running away during certain exercises
• Reluctance to shoe and difficulty passing urine and faeces
• Refusal to lie down or roll around in the box
• Difficulties with the reins
• Incomplete transitions
• Issues with rein contact and incomplete transitions
• Behavioral changes such as biting and kicking, difficulty catching
• Reluctance to move backwards

Causes of kissing spines in horses

Kissing spines and related back issues in horses are often the result of improper riding and inadequate training. One common cause is placing a rider’s weight on a horse’s back before the horse has developed sufficient muscle strength. Young horses, in particular, may not have enough time to build the necessary skeletal and muscular support.
The back muscles are essential for supporting the horse's skeleton. When a rider mounts, the horse's spine initially gives way. To carry the rider’s weight healthily, the horse must engage its long back muscles. If these muscles are not strong enough or are tense, they cannot function properly, leading the horse to push its back down instead of arching it. This incorrect loading causes the spinous processes of the spine to move closer together, leading to painful rubbing or even overlapping.

Continued incorrect loading can cause inflammation in the back muscles. Over time, this inflammation can lead to muscle atrophy, reducing the protection of the spine and causing the horse to feel strain directly on the bones. The 12th to 18th thoracic vertebrae are particularly vulnerable, as they are close together and located directly under the saddle. This area is prone to excessive strain due to the rider's weight and the reduced tensile stress from the head and neck. Consequently, this can lead to increased muscle tension and compression in the saddle area, exacerbating the problem.

Diagnosis and Treatment of Kissing Spines in Horses

How is Kissing Spines Diagnosed?

Kissing spines are primarily diagnosed through X-rays, which can reveal the bone changes associated with the condition. However, X-rays only show the bone structure and may not fully capture the extent of inflammation or pain. Even in horses with healthy backs, some bone changes or narrowing of the spinous processes may be present, which might not be immediately concerning but could indicate a potential risk for future issues.
A comprehensive diagnosis involves a combination of clinical examination and radiographic imaging. Clinical assessments include evaluating the horse’s symptoms, behavior, and response to palpation, while X-rays provide detailed images of the bone structure. Together, these methods offer a complete picture of the horse’s condition, allowing for accurate diagnosis and effective treatment planning.

Therapy options for horses with kissing spines

The primary approach for managing kissing spine syndrome in horses is to allow for free movement. Encouraging the horse to move freely helps to relieve back tension more quickly. Another crucial aspect is to ensure that the horse is free from pain, which can be managed with painkillers and anti-inflammatories. 

Once the horse is largely pain-free, osteopathic treatment can be introduced. An osteopath will assist in restoring the horse's basic mobility, while the owner will be taught simple exercises to help maintain this mobility.

In addition to pain management and osteopathic care, correct hoof trimming and a properly fitting saddle are essential. To build up the back muscles, working from the ground over several weeks (6 to 12 weeks) using methods such as double lungeing, pole work, and Equikinetic is often more effective than riding an aching back. During this period, muscle-building micronutrients like amino acids, vitamins, and trace elements can support muscle development and overall recovery.

A well-structured training program is crucial to strengthen the back muscles and enable a return to riding. It is important to focus on developing well-trained back muscles that stabilize the spine and prevent further deterioration. In addition to lunging, work in hand—including exercises such as lateral movements—is recommended. Later, integrating intensive, relaxed riding in a forward-downward direction, along with regular rein chewing, can positively train and strengthen the back muscles.

In most cases, various treatment methods are combined:

• Drug treatment

Use of paramedical methods such as chiropractic, acupuncture, physiotherapy (heat, swimming training, electrostimulation), homeopathy

• Use of feed supplements containing chondroitin or glucosamine
• Surgical interventions in rare cases

Depending on the severity of the kissing spine syndrome and the horse's perception of pain, treatment options may vary. Anti-inflammatory medications or medicinal herbs can be used to manage pain and reduce inflammation. Supplementary feed often plays a supportive role in the recovery process. For many horses, adding glucosamine, chondroitin, hyaluronic acid, and MSM to their diet can be beneficial. Additionally, ensuring a high-quality supply of essential amino acids, vitamin E, and selenium is particularly important for supporting muscle health and overall recovery.
Surgical intervention is generally considered a last resort and is not commonly recommended. This is because the issue often involves not only the spinous processes but also the articular processes on the vertebral body. Therefore, addressing the problem with non-surgical methods is usually preferred.

How do I prevent kissing spines?

• Pay attention to changes in your horse's behavior and performance. Take early signs of back problems, such as discomfort or refusal to work, seriously. 
• Being overweight puts additional strain on the back. A balanced diet and regular exercise to maintain a healthy weight are important. 
• Your horse needs sufficient rest to regenerate its muscles. Plan rest breaks and breaks from intensive work. 
• Close contact and communication with your vet is crucial to monitor your horse's condition and adjust the treatment plan. 
• A qualified physiotherapist can provide valuable support during treatment. 
• A well-fitted saddle is of great importance to minimize pressure on the back. 
• Develop an adapted training program that takes your horse's needs into account. 

Working horses with kissing spines

In addition to lunging, working in hand is highly beneficial for horses with kissing spines. Basic exercises, such as leg yields and halt-backs, help to loosen the muscles and enable the horse to internalize commands with vocal cues. As the horse progresses in its training, it will start to connect commands with the appropriate aids, which is crucial for effective riding.

If you are inexperienced with work in hand, it is advisable to seek professional guidance. Be sure to communicate to the trainer that the focus is on foundational exercises rather than advanced maneuvers like piaffe and passage. Work in hand can complement under-saddle work but should be approached carefully to avoid causing additional strain.

Cross-country work is an excellent opportunity to practice letting the reins out of the hand. On large curved lines, forest trails, or meadow paths, this technique is indispensable. It teaches the horse to stretch its back, engage its hind legs, and use its muscles correctly while allowing the horse to relax. Proper execution of this exercise helps the horse achieve a posture where the nose is at or slightly in front of the front joint, which facilitates stepping under the center of gravity and causes the back to swing.

Incorporating the exercise of letting the reins out of the hand regularly in both the arena and the field helps ensure that the horse remains supple and balanced. This practice helps to load all muscles, tendons, ligaments, and joints correctly, releasing tension and promoting overall suppleness. It is essential to include this exercise not only at the beginning and end of training but also throughout the session.

To prevent back problems, it is crucial to focus on training that promotes relaxation and effective movement. This includes working on transitions, speed variations, and lateral movements such as shoulder-in, travers, and renvers. Proper half halts, especially on the outside rein, encourage the horse to accept the bit and push off correctly. Strengthening the back muscles is key to stabilizing the spine and preventing further deterioration. With this approach, many horses with kissing spines can be trained to advanced levels and ridden comfortably into old age.

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