Updated: Mar 13
Sesamoiditis is a chronic degenerative disease of the sesamoid bones. This simply means that the sesamoid bones are slowly disintegrating. Many individuals tend to make the condition more important than it actually is. It seems that oftentimes when there is difficulty in reaching a definitive diagnosis, sesamoiditis is given as the reason for the unsoundness.
It occurs most commonly in the older horse, or in the horse where surgery has been performed on the sesamoid bones. When the condition is severe, it can indeed cause lameness, in some animals a head nod may be apparent. On palpation, the area of the sesamoid bones may be warm and painful. X-ray examination of the area will aid greatly in reaching a diagnosis. The greatest problem here is that so many horses, especially those five years or older, may show evidence of a sesamoid problem. Those animals severely affected, will have sesamoids that look more like swiss cheese than hard, dense bone. A definitive diagnosis is reached by locally blocking out the area of the sesamoids with a local anaesthetic.
Sesamoiditis is usually an ongoing, smoldering disease, in which it is almost impossible to cure. The best most of us can do is to control it rather than cure it. Applying a good deal of heat to the area by way of hot paints and blisters, may allow for some healing, especially if this accompanied by stall rest. Injecting the area with cortisone, or injecting the fetlock joint with cortisone may also relieve the pain temporarily, but the bone will continue to get weaker.
As mentioned above, sesamoiditis is a common sequel to sesamoid surgery. i.e the removal of sesamoid chips. It is thought that bringing the horse back to the too quickly after surgery, predisposes the animal to this condition.