Kissing Spine is a problem that is basically what it says on the tin. Sections of a horses vertebrae (the bits that stick up above the actual spine, dorsal spinous processes) rub together and impinge each other, very quickly becoming incredibly painful.
The horses spinal chord is split into sections, the cervical vertebrae – which is from the skull down the horses neck, to the thoracic (from the base of the neck to where your saddle sits) to lumbar vertebrae – generally towards the back of a saddle to the highest point of the hind end – then you have the sacral vertebrae (which is fused) and caudal/coccygeal vertebrae, which make up the latter part of the spine through the hind quarters and your horses tail bone. Your horses withers are made up with thoracic vertebrae that have larger dorsal spinous processes that form the ridge we see at the base of our horses necks.
A horse that has Kissing Spine will be in near constant pain, from very low grade to bad enough to cause dangerous, unpredictable behaviour. Horses with kissing spine can go for years without it being diagnosed, because unfortunately the symptoms can be very subtle. In my geldings case (and what is often found in a lot of horses) he couldn’t maintain a canter unless in straight lines and fell out of it, or bunny hopped / motorbiked around corners to power himself onwards. He began to refuse jumps (which he never ever did) and got to the point where he was bucking in the corners of the arena; where his spine moved more to bend round a corner and became more painful. His symptoms didn’t all present at the same time, every day and we actually only found out about his KS as he went lame in his hind end and went into Leahurst for a full body bone scan.
A fair amount of horses have kissing spine, but it’s often higher-performance horses in which the condition is noticed (certainly quicker!) as happy hackers mainly do lots of straight lines with little bending being asked of them.
Horses with a higher severity of kissing spine may become irritable when being groomed over their back as well as being unhappy being saddled & rugged up. They often buck when ridden, which can develop into more dangerous behaviour. This behaviour will usually become more frequently/strongly displayed the longer the condition goes untreated and unfortunately often horses become aggressive and dangerous under saddle. Freddie didn’t show any of these symptoms, however he wouldn’t tolerate being sat on bareback and exploded whenever anyone bigger than me got on him. It turned out, that where his kissing spine lay was towards the back of the saddle. Because i’m so small (5’2 midget) I didn’t push the back of the saddle down much, but anyone taller or heavier than me did, which caused his explosions.
These were Freddie’s scans upon his diagnosis of Kissing Spine. You can see the difference between the normal spinal processes and the KS areas. The white marks on the bone is damage caused by the processes touching; you can see how close 2 sections are in the scan directly above as well as the spinal processes more to the right totally touching/overlapping, ouch!
Kissing Spine can be caused by multiple things; unlike in a lot of cases for domesticated horses it isn’t always what is done with the horse by people that causes Kissing Spines. Conformation can cause it; for example a horse that is very short backed may be more likely to suffer from the condition in the future as there quite literally isn’t as much room between the vertebrae as a long backed horse of the same size has. Damage to the spine can also be done by horses generally being poorly put together, which is why breeding should be done so carefully. Horses that work hollow are also more likely to do damage, as the spine is flexed in more of a smile shape rather than the centre of the back lifting upwards to support the horse.
There is no doubt that Kissing Spine can also be caused by what we as humans do with our horses. A high-performance sports horse that takes a lot of impact down it’s back and spine (a 4* eventer, for example) will typically have more wear and tear on it’s body than a happy hacker. In Freddie’s case, he was in heavy work before his body had finished developing, which has (we are 99% certain) caused his damage.
Treatment of Kissing Spine in the modern world we live in can be varied. A lot of people go for injections & rehabilitation first, with surgery being the last option. Surgery can involve removing the sections that are causing problems, reshaping them so they no longer touch & cause pain. Physiotherapy is important in cases of kissing spine, as often the condition goes undetected for a while, which causes horses to over-compensate with other parts of their body to avoid the pain as much as possible. Fred for example was also diagnosed with Proximal Suspensory Desmitis, which more often than not is secondary and caused by something else. (In this case, over compensating with his hind end to avoid his back hurting, and so in time damaged his suspensory ligaments.)
Kissing Spine is a very common condition among horses and I’d be prepared to bet if you scanned a yard of 100 horses, you’d be surprised how many had some form of ‘hot spot’ show up. Depending on the severity of the condition will alter the course of treatment and recovery. Often, horses with kissing spine that are retired to grass will manage perfectly normally with no treatment. Using physiotherapy and treatment, horses often come back into full work and can be back out competing the same year. It is important to keep the horses whole body in mind when treating and rehabilitating something with kissing spine, as to support the back sufficiently the horses have to learn to engage their core and step under with their hind end properly. This takes time and patience on our part, especially when dealing with horses that have had the condition for a long time as you can’t tell them that they don’t need to move in a wonky way any more and that their back wont hurt again! They have to build their muscle up slowly while effectively re-learning how to move like a normal horse.
It’s very much doable, which is a bonus for all of us (humans and our equine friends) as now Kissing Spine no longer has to spell retirement or worse in most cases.