Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Overriding Dorsal Spinous Processes

Synonyms: Kissing Spines, Spinous Process Osteoarthritis


The spinous processes are crests of bone along the spine that project upward from the vertebrae. They function as attachment sites on the spine for top-line back muscles. In most cases there is a variable, small gap between these adjacent bones.

In this condition, also known as "Kissing Spines", they are in contact with each other, impacting one another in movement.

This is a potential cause of poor performance and back pain especially among dressage horses, hunters and jumpers. It is more common in Thoroughbreds.

There is debate over whether or not this condition causes pain. Some horses with this condition do not appear to be in pain, and perform well at their intended discipline.

Diagnosis is clinical exam, radiology, nuclear medicine and, to some extent, ultrasound. If radiographs confirm contacting spines, local anesthetic may be injected into the area to see if performance is changed.

Treatment is either medical or surgical. Surgery involves procedures to reduce contact of bone on bone between the spines. A more recent procedure involves cutting the short thick ligament between the adjacent vertebrae at this level.

my vet's role


Treatments May Include

These treatments might be used to help resolve or improve this condition.

Very Common
Less Common
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The prognosis is fair to good with either medical or surgical treatment. But other conditions may coexist with this one.

Disc disease or arthritis of the vertebral joints complicates the problem, and worsens the prognosis.

my role


I might observe

You might make these observations when a horse has this condition.

Very Common
Less Common
more observations

Questions To Ask Your Vet:
  • How do we know this is the cause of pain, and not something else?

Select horses with appropriate back structure, a moderate back length.

Rounding of the top-line through balanced riding and collection and strengthening of the top-line with proper exercise (long and low) helps separate the spinous processes and lessen the problem.

further reading & resources

Author: Doug Thal DVM Dipl. ABVP