The comfort and health of the horse’s withers is a central key to its performance and soundness.
The withers are the part of the spinal column that lies in between the animal’s shoulder blades and includes the third to 11th thoracic vertebrae. Collectively these vertebra project upwards into an arch.
Their uniquely prominent (tall) spinous processes act as anchor points for the attachment of numerous elastic ligamentous and connective tissue structures that suspend the forelimbs and neck, bridge the back, as well as interlace the hindquarters into the fascial net of the body.
As such, the withers are much more than a reference point for measuring the horse’s height.
They play a pivotal role in the biomechanics responsible for the fluidity of the horse’s movements, and thus any disturbances to the tissues in this region, even seemingly small ones, affect its way of going, athleticism and soundness.
Problems with the withers can have subtle and confusing presentations due to the sophisticated nature of their connections to the whole body of the horse. Technically, wither pain is an alternative presentation of back pain, which has a direct bearing on movement quality for leg movement.
Sensitivity, swelling and heat in the area of the withers would clearly indicate a problem, however, more subtle changes must also be observed. The physical shape of the withers needs to be evaluated for side-to-side and front-to-back symmetry, smoothness and contour. Healthy withers are ‘full’ rounded, symmetrical, comfortable, and blend smoothly and evenly with the shoulders and neck.
Lateral (left-to-right asymmetry) or ‘sinking’ of musculature in the pockets on one or both sides is indicative of muscular imbalance or atrophy (loss). These findings warrant further investigation for pain or imbalance elsewhere in the body as well as evaluation into the movement or compensations that have contributed to the unusual shape/development of the withers.
The physical appearance of the head-neck-shoulder hookup in a horse is highly influenced by its posture and carriage. The seven neck vertebral bones make an S shape, with the top curve right behind the skull and the bottom curve joining the thoracic vertebrae in the area at about the level of the shoulder joint. The cervical vertebrae are located in the lower third of the neck, not the top as is commonly thought. The base of the neck connects and transitions into the rising arch of long spines of the thoracic vertebrae that form the withers.
If the lower S part of the neck or its base falls forward as a result of weak muscle development in this region, it causes the base of the neck to drop. Due to the sophisticated ‘hookup’ with the withers, the poorly supported base of the neck ‘falls’ and draws the topline down creating a dip in the front part of the withers. This dip can be found from broodmares to high-event sport horses, and is comparable to slouching in people.
Poor development of these muscles that sling the base of the neck can come about when a horse lives a sedentary life and lacks condition. However, this dip can be due to handling techniques or work that does not cultivate the elevation of the base of the neck, balance and carriage. Over time, the shape and health of the withers are strongly influenced by the movement patterns of the horse, handler/rider contact and lifestyle.
Proper saddle fit is extremely important. Although saddle fit can be responsible for creating wither pain, it can also be unfairly blamed when it exposes or amplifies back problems already in existence. Horses with a ‘hollow’ back or with a defensive topline will challenge any saddle fit. If saddle fit becomes the scapegoat, the root cause(s) for the sore withers may remain unaddressed. Teeth issues, poll issues, gut issues, and other problems that increase tension along the topline present a back that becomes increasingly difficult to saddle fit. Overconditioned and underconditioned horses also present a unique challenge because as body shape changes so does the saddle’s fit. The contribution of saddle fit to the overall equation of the horse’s performance also becomes progressively more relevant as the workload upon the horse increases.
The width of the saddle tree is a key factor. Trees too narrow place pressure on either side of the withers while trees too wide place pressure on the top of the withers. If the injury from saddle pressure goes unrecognized in its early stages of tenderness and heat, white hairs later appear at the pressure points due to injury of the hair follicles. If mild, hair will remain white for one coat cycle, however, if damage is severe the area will remain white for the lifetime of the horse. Compression injuries may result in palpable scar tissue and fascial tie-down of the skin in the afflicted area. The skin over the withers may appear to ripple and wave as pressure forces have sheared and injured the connective tissue layers beneath.
Ill-fitting blankets can also cause pressure injuries over the withers region or bind the base of the neck and thus become problematic to wither health. Other factors are elevated hay nets and/or bags, overlongeing especially if the horse is longed in poor form, uneven or excessive tension on the reins, and incorrect use of equipment such as draw reins or chambons.
Horses can really benefit from a gentle check of the withers for sensitivity, health of tissue, muscle development, pain, white scars, fascial tie-down, and symmetry.
The condition of the horse’s withers can then provide invaluable clues about the horse’s overall physical condition, athleticism and well-being.