Kissing spines (overriding dorsal spinous processes), where the vertebrae are too close together to the point of touching or overlapping, is a cause of back pain in horses. New research shows the condition may be hereditary.  A research team found chromosomes 16 and 25 appear to have regions that affect the severity of kissing spines in warmbloods, thoroughbreds, and stock horses.  At the AAEP convention, Dr. Samantha Brooks from Florida and Dr. Beau Whitaker from Salado, Texas presented that a third chromosome, number 14, appears to be associated with the presence of kissing spines in affected horses and determines if the disease is present in a specific horse.  Because of this, it is not recommended to breed horses with kissing spines. The researchers have been performing genetic testing on horses without kissing spines to locate genes responsible for the disease and found that changes on chromosome 16 increased the chance of kissing spines by one grade while changes on chromosome 25 increased the chances of kissing spines by two grades.  So, a horse affected with both genes has a three grade increase in chances of having a kissing spine, and this is not a small amount.  The horse’s height also increases the chance of kissing spines, but age and sex of the horse have less impact. 

This new information is worth checking out before training a horse since affected horses should have a less strenuous career such as leisure riding versus upper-level dressage or reining.  Also, if you know your horse is at risk and the horse seems painful or has decreased performance, the horse’s back is one area to examine first.  Treatment for kissing spines can be injections in the back or surgery. Surgery seems to be the most effective.  Hopefully, further research will aid in decreasing this equine problem.