Head Position Impacts Kissing Spines Evaluation (AAEP 2012)

A horse’s head and neck position during radiographs might influence how veterinarians interpret the images when diagnosing spinous process impingements.

This painful equine back condition is commonly called “kissing spines,” a term that describes how adjacent vertebrae of affected horses touch or rub against each other. Veterinarians rely on radiographs to help diagnose this condition, but since horses hold their heads at different heights, depending on their conformation and whether they’re alert, calm, or sedated, a research team wondered whether this variability could impact diagnostic accuracy.

Dagmar Berner, DVM, a resident in the European College of Veterinary Diagnostic Imaging program at the Faculty of Veterinary Medicine at the University of Leipzig, in Germany, and her colleagues examined how such head and neck positions impacted distances between thoracic vertebrae (which begin at the point of the shoulder and continue to where the last rib attaches to the vertebral column). She presented the team’s results at the 2012 American Association of Equine Practitioners convention, held Dec. 1-5 in Anaheim, Calif.

The team hypothesized that low or high neck positions would increase or decrease intervertebral distances, complicating kissing spine diagnosis.

The team took lateral (from the side) radiographs of 23 healthy horses holding their heads and necks in three different positions:

  • Normal, with the horse's mouth at his shoulder level;
  • Low, with the horse's mouth at his knee level, similar to the stance sedated horses often adopt; and
  • High, with the horse's mouth at his wither level.

After taking radiographs, the team measured the distances between adjacent spinous processes.

They found that a low head and neck position increased intervertebral distances from the 8th to the 15th spinous processes. Not surprisingly, a higher head and neck position essentially compressed the spine, decreasing the distance between vertebrae, Berner reported.

She also stressed that even if veterinarians see variability on radiographs, there is no guarantee that tight intervertebral spaces actually cause the horse back pain.

Berner concluded that veterinarians should take the horse's head and neck position into account when evaluating radiographs to diagnose kissing spines. She recommends aiming for a "normal" head and neck position to obtain the most accurate measurements of the distance between spinous processes; the most accurate measurements will lead to the most accurate diagnosis.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.