Overriding dorsal spinous processes AKA ‘Kissing spines’

June 4, 2022

What is Overriding dorsal spinous processes / kissing spines?

Reduced space between the dorsal spinous processes (DSP’s) of the spinal vertebrae or touching spinal processes is called ‘overriding dorsal spinous processes’. Also referred to as ‘kissing spines’.  As it’s a condition that can cause pain and poor performance in horses our nurse technician and physiotherapist Charlie Coyle has compiled this complete guide.



Common symptoms of a horse with overriding DSP’s may include:

  • Difficulty in transitions
  • Sensitivity to brushing / touching the back
  • Hollowing of the back
  • Difficulty building topline muscle
  • Poor performance during ridden exercise, including unwillingness to go forwards, bucking, rearing, shooting forwards and lack of impulsion
  • Stiffness throughout the back
  • Becoming difficult to mount



X-rays are used to diagnose overriding DSP’s. The significance of x-ray findings is often backed up with a comparative dynamic assessment of the horse.  This is done twice, once before and once after nerve blocking of the back, where a local aesthetic is injected between the affected dorsal spinous processes. Caution must be exercised in over interpretation of x-rays alone without a dynamic evaluation.



Some horses with kissing spine can be treated with conservative management and rehabilitative exercises alone. For others, treatment can involve medication of the affected interspinous spaces.

In some cases, surgery is required. Surgery options include interspinous ligament desmotomy and a DSP resection/ostectomy. The first involves the cutting of the spinous ligament to create a greater space between the affected DSP’s. The DSP resection/ostectomy option involves portions of the close DSP’s being removed.


Rehabilitation post-back medication and DSP surgery

Regular physiotherapy and implementation of a rehabilitation exercise plan post treatment is key for the horse’s recovery and success in returning to work. Veterinary physiotherapy sessions may include massage therapy, myofascial release, stretching exercises and use of electrotherapies. The veterinary physiotherapist will also be able to demonstrate stretches and exercises for you to carry out with your horse between treatments.

Key benefits of physiotherapy include the fact that:

  • It accelerates the rate of healing
  • It reduces scar tissue formation post surgery
  • If offers pain relief
  • It increases suppleness and flexibility
  • It improves joint range of motion and stride length
  • It increases proprioception and straightness


Rehabilitative groundwork exercises

Following surgery, horses undergo two weeks of box rest before starting rehabilitative exercise.  This often includes walking in hand, long reining and pole work.  The aim of theses exercises is to increase muscle mass and strength over the horses back.  During this time, it is advised for the horses to be exercised 5-6 days a week.  The horse needs to be exercising most days to prevent formation of muscle adhesions and fascia contraction. However, rest days are also important for recovery when building muscle.

Exercises are progressive, so both the length and intensity of exercise sessions increases week by week. Another good example of this progressive regime is when we move from walking over poles on the ground, to raised poles, followed by grids and combinations of poles.

Gradients and training aids such as a Theraband, can be introduced later in the rehabilitation to activate and strengthen the core and hindend muscles, which in turn will support both the back and the horses overall posture.


Return to ridden exercise

On average, most horses return to ridden exercise 16 weeks post surgery, however this varies case by case. Following back medication, horses usually follow a 3-4 week programme of groundwork exercises before returning to work under saddle. Once the rider is back in the saddle, we progress from walk work, to trotting and canter before jumping exercises are re-introduced.  This allows the horse to gradually build strength and endurance in the long back muscles whilst also aiding it to overcome any association between ridden exercise and pain.

Each horse requires a unique rehabilitation plan tailored to their individual case.

DSP Before:

DSP before

DSP After:

DSP after surgery

*Please note that the white ring in the middle of the back is just a surgical staple which is removed.

Get physiotherapy for your horse

If you would like to discuss physiotherapy for your horse, please contact Charlie Coyle EEBW BSc (Hons) MNAVP MSc Veterinary Physiotherapist. Charliecoylevetphysio@outlook.com. 07944165989.


Charlie Coyle EEBW BSc (Hons) MNAVP MSc

Charlie joined Towcester Equine Vets in early 2019 after graduating from Writtle University College with a degree in Equine Sports Therapy . Having since completed a Masters in Veterinary Physiotherapy, Charlie uses her knowledge of equine anatomy to assist with our poor performance caseload and ongoing rehabilitation.


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