25/03/2022
What are kissing spines and what are the signs/treatment options?
Here's an excerpt from Stuart's Ask the Expert from Your Horse Magazine:
Kissing spines are a relatively common cause of back pain in horses, and the source of the problem is an issue with the vertebrae in the horse’s spine. Individual vertebrae are connected by ligaments and surrounded by muscles, and each vertebra has a bony prominence pointing up to the skin’s surface called the spinous processes. Normally, the spinous processes are evenly and adequately spaced - which allows the horse to move and bend without issue. But with kissing spines, these spinous processes are too close together - and can even touch - which causes pain and reduces mobility. Kissing spines often occur in the last few thoracic vertebrae just where a rider would sit on the horse’s back.
Signs of kissing spines can be similar to other back conditions and include showing discomfort when saddling up or being groomed over the back, having poor performance and mobility issues and temperamental changes when in work, a reluctance to be ridden, becoming difficult to mount, and particularly can struggle to maintain a canter when riding.
The process of diagnosis would include a full history and physical examination, lameness investigation including local anaesthetic (similar to nerve blocking), and then finally imaging of the back typically including X-rays, bone scans or ultrasounds to determine whether the bones or ligaments are the potential cause of the issues.
Treatment options
Just like when dealing with foot conditions where a farrier is essential, I find physiotherapy (with strengthening exercises and good core work) as essential for a good outcome when dealing with back issues. Once diagnosed, as your vet I would work hand-in-hand with a physio to increase mobility and strength along the horse’s topline. To facilitate this, sometimes medication can be used - often a skeletal muscle relaxant can be given orally which will help maintain a nice rounded outline. This can be used alone or in combination with anti-inflammatory injections between the spinous processes or along the muscles of the back.
Conservative medical treatment can often yield impressive results even in horses suffering from kissing spine. But, in some cases surgery remains a useful option, and is designed to widen the spaces between the spinous processes. This is commonly done now in the sedated, standing horse avoiding the need of general anaesthesia.