Defining Withers

• According to Janet Roark, a veterinarian in Austin, Texas, "withers are comprised of the dorsal spinous processes of T2 through T6 of the thoracic vertebral column." To more fully understand this, know that the horse's back is made up of 18 thoracic vertebrae, five or six lumbar vertebrae at the loins, and then the sacrum, at the rear or pelvis. T2 to T6 are the second through sixth vertebra of the thoracic vertebral column.
  
  

Purpose of Withers

• The withers help hold the saddle in place.BananaStock/BananaStock/Getty Images
  
  Dr. Roark states that the horse's withers act as a fulcrum: "As a horse lowers and extends its neck, the back rises." In addition, the withers hold the saddle back and in the proper place, keeping the saddle off the top of the scapula and middle of the neck. The saddle needs to remain in the middle of the back without excessive pressure from the girth on the rib cage.
  
  

Defining Mutton Withers

• If the saddle falls forward, it can severely restrict a horse's shoulder movement which is important in performance.Comstock/Comstock/Getty Images
  
  In a mutton-withered horse, the dorsal spinous processes, which are the upward-pointing bony blades that define the withers, are short, making the withers appear flat. Dr. Roark notes that there is no measurement that defines a mutton-withered horse. "I personally would not consider a horse mutton-withered unless it actually causes difficulty with saddle fitting or physically limits the horse's ability to raise its back," Dr. Roark stated. The primary problem is with saddle fit; if the saddle slides forward, the horse's shoulder movement is restricted, putting more weight on the forehand and interfering with the horse's balance.
  
  

Owning a Mutton-Withered Horse

• Invest in a professional saddle fitting, particularly for the mutton-withered horse.Jupiterimages/liquidlibrary/Getty Images
  
  Some horses do have a predilection for very low or mutton withers, such as Quarterhorses, but any breed can produce mutton-withered horses. While it is considered a conformational defect, Dr. Roark emphasizes that the main reason these horses may not be able to perform to their natural ability is poor saddle fit. "It's essential to do a professional saddle fitting if you have a horse with mutton withers and you plan on doing any performance work with them," Dr. Roark stated.