Kissing spines or dorsal spinous process impingement may be sudden (provoked by a traumatic incident such as a fall) or insidious in onset, presenting as a progressive unwillingness to work or a deterioration in performance. In some cases the condition is a congenital defect but can present at any age. Generally the condition is seen more in dressage, event and other competition horses. This is possibly due to the greater physical demands placed on them as in many cases the problem may go unnoticed in horses used for hacking and low-level work.
Cause of pain
The horse’s back is comprised of 18 thoracic vertebrae and five or six lumbar vertebrae and the sacrum. Each vertebra has a dorsal spinous process (DSP) — a thin, bony blade that projects upwards. The spacing of the dorsal spinous processes is dependent on the horse’s conformation. The shorter the horse’s back, the closer the DSPs are likely to be. A horse with this condition may experience consistent, low-grade pain because the spinous processes, or bones projecting from the vertebrae, are too close together and impinge on each other. Extra bone develops as a result and compresses the soft tissue.
Back pain rarely causes overt lameness, but it may result in reduced stride length in front and behind, reduced hindlimb impulsion and stiffness. The longer the problem is present, the more likely it is that the horse will lose muscle off the top line because he is protecting his back and not using the muscles properly.
Definitive diagnosis is dependent on a careful assessment of the horse, X-rays and a positive response to infiltration of local anaesthetic solution around the affected dorsal spinous processes when ridden.
- Corticosteroid Injections: this is a deep injection between the affected spinous processes and aims to reduce surrounding inflammation and associated pain.
- Shock-wave therapy.
- Use of Tildren appears to be beneficial in some cases of kissing spines, however strong clinical evidence of this success is yet to be published.
- Surgery: this involves cutting and removing the dorsal affected dorsal spinous processes and some associated soft tissues.
- An extended period of rest may cure kissing spines in some horses.
- Alternative therapies including acupuncture, chiropractic manipulation, laser and magnetic therapy may also alleviate symptoms but in the majority of confirmed cases of kissing spines this improvement appears transient in our experience.
DISCLAIMER: This advice is intended for use by registered clients of Priors Farm only. The advice offered is general advice only. Priors Farm clients who wish to discuss the individual circumstances of their horse should contact the office. To speak to a vet please phone between 8.30 – 10.00 am on weekday mornings.