Vet Vibes: Diagnosing kissing spine

VET VIBES

Diagnosing kissing spine

Could kissing spine be the cause of your horse’s behavioural issues? RACHEL ROAN spoke to Dr Calum Paltridge to find out.

When behavioural problems in horses arise and owners begin to search for the root cause, back pain should always be on the list of issues to rule out – and kissing spine is one condition that vets often look for. processes, where the vertebrae along the spine narrow and rub together, resulting in changes to the bone, restricted mobility, pain and discomfort. “The dorsal spines are basically the pointy bits of bone that come up from a horse’s spine,” Dr Calum Paltridge explains. “The most obvious dorsal spinous processes are at the wither, but they exist all along the thoracic spine. In horses with kissing spine, the space between those spinous processes has narrowed between adjoining vertebrae, and they rub against each other, causing pain.”

Often, a horse with kissing spine will appear sound in the paddock, and it’s only under saddle that symptoms really show. The weight from the rider on their back causes the spine to sink, so the dorsal spinous processes become closer, rub together, and exacerbate the pain.

Research into kissing spine is still at a preliminary stage, but it’s broadly believed that a variety of factors may play a role in its development. “While we don’t know the direct cause for kissing spine, there are a number of potential reasons,” Calum tells me. “It may be partly due to genetics, partly conformational, or it could be injury related.” (Follow the link for a recent study on the kissing spine gene).

ABOVE: Back pain should always be on the list of issues to rule out in a horse with behavioural problems.

The strength of a horse’s back and their overall muscle strength and tone also has an impact – particularly when carrying a rider. The size and weight of the rider in comparison to the horse should also be considered.” It would also be unwise for a poor, skinny horse to be ridden, as it would put them at risk of back-related issues. “Horses that are wasted away or lack topline struggle a lot more to maintain their posture,” Calum adds.

Signs of kissing spine are often varied. “The first thing a lot of owners notice is reluctance under saddle; whether that’s over a jump, unwillingness to go up or down hills, or girthiness. Riders sometimes misinterpret the horse as being girthy when they are actually just sore from the pressure of the saddle on their back,” he notes. Pain when a rider mounts or dismounts is another sign that something could be wrong.

An initial examination of the horse involves the vet pressing along the spine looking for soreness. Calum explains that horses without back soreness dip their back away slightly from the pressure, while horses that are in pain will either hold themselves entirely rigid to avoid moving their back, or, they will make an exaggerated move away from the pressure, indicating signs of significant soreness through the axial muscles of their back. “It’s a bit of a grey area,” he admits. “Similar to back pain in people, the reason can sometimes be hard to determine. What produces pain in one horse while another horse with very similar x-rays is fine is something we are yet to understand.”

Before concluding a horse has kissing spine, it’s important to first rule out other potential sources of their discomfort. Arthritis, tendon and ligament issues, poor teeth, or a badly fitting saddle are some of the areas that should be explored. “Other things that can produce back pain, like arthritis in the spine, need to be considered,” says Calum. “Gastric ulcers can also cause horses to perform poorly or become a bit girthy, and they can present with a varied array of symptoms. Ideally these things should be ruled out first on the list of performance issues to check for.”

A diagnosis of kissing spine can be reached through a combination of clinical signs and x-rays. An x-ray of a normal spine will show nicely spaced dorsal spinous processes that are not touching and have clean margins. In comparison, the spine of an affected horse will have close or touching spinous processes, and often changes to the bone are visible from where they’ve been in contact. “Bone on bone will obviously bring about a reaction and we will see loss of bone, calcification, or other changes,” says Calum.

However, an x-ray alone is not enough to provide the full picture. In a 2011 study, over a third of horses with no signs of back pain had evidence of overriding spinous processes on x-rays. The study found that many ridden horses showed evidence of kissing spine, without any of the accompanying signs of pain or behavioural issues. In some cases, horses were physically conformed to display kissing spine, yet still showed no signs of discomfort. It is not known whether in these horses, their condition will evolve into a problem later on. In addition to the evidence on an x-ray, an accurate diagnosis relies on the horse showing signs of being sore in the back. “Ideally, we should be able to nerve block this with local anaesthetic to prove that’s definitely where the pain is coming from. That, in combination with x-rays, indicates kissing spine could be the issue,” Calum tells me.

For horses affected by kissing spine, having someone on their back can cause noticeable pain, and their performance may become very limited. Many disciplines require flexion and a high range of movement in the back, which might be challenging and difficult for an affected horse. So what can you do when you receive a diagnosis of kissing spine? For mares, breeding is not ruled out. “You would just want to ensure the stallion you choose has really good conformation, and make sure that they don’t have similar issues, as there may be a genetic component,” explains Calum.

As daunting as this condition may sound, he believes owners shouldn’t worry unduly as a variety of treatment options are available. Many horses can

Equine Clinical Nutrition

be managed well through physiotherapy and strengthening, or for more developed cases, surgery is also an option. “Although expensive, there are a couple of different surgeries which can be quite effective, but you have to be certain that kissing spine is definitely the issue,” he stresses. “Depending on the horse, many can be effectively managed through exercises that build topline and strengthen the back. There are a number of exercises known as carrot stretches, which focus on stretching those muscles in the back and building topline.”

Working horses in hand to encourage them to drop their head and build topline can successfully reduce symptoms, and other treatments such as shockwave therapy and acupuncture have also been successful. In the

middle ground between strength exercises and surgery is the option of cortisone injections. These are most effective in combination with

physiotherapy to build muscle. X-rays, nerve blocks, physiotherapy and cortisone are all relatively inexpensive.

Calum points out that people can be too quick to look for a physical reason behind any behavioural problems. “Sometimes they need to review their training processes first. They may be pleasantly surprised to discover that there is nothing physically wrong with their horse after all.”

While back pain in horses can be complex, there are many treatments available to help make your horse happy to have you back in the saddle. With correct management, kissing spine doesn’t have to mean the end of your horse’s career.

Dr. Calum Paltridge (BVSc (Hons) MANZCVS) is the owner and veterinarian at Thunderbolt Equine Veterinary Services in Armidale, NSW.