Splints may be unsightly, but they don’t usually cause a horse too many problems. Vet Leona Bramall explains how they should be managed.
Splints are bony enlargements (exostoses) of the interosseous ligament that connects the splint bones to the cannon bone.
Inflammation and mineralisation of the ligament causes a surface bone reaction to the splint and cannon bones, resulting in the development of small to large bony lumps which can be felt around the splint bone region of the lower limb. Splints can occur throughout the year, but there is a higher incidence during the summer months.
For the most part, splints are cosmetic blemishes that don’t interfere with a horse’s long-term athletic ability.
However, some can result in significant lameness, especially in the immediate injury period or, in rare cases, where there is impingement of the suspensory ligament.
Each limb has two splint bones: the medial (second metacarpal bone, MC2); and the lateral (fourth metacarpal bone, MC4), which course on either side of the back of the cannon bone.
Splints generally affect the top third of the affected bone, but they are certainly not limited to this area and can occur in any part throughout the length of the bone.
The medial (inside) forelimb splint bone is most commonly affected, but splints may occur on the lateral (outside) forelimb splint bone, or indeed on either hindlimb splint bone, although this is less common.
Splints can occur as a result of trauma, foot imbalance, or secondary to poor knee conformation, namely bench knee. Young horses are more commonly affected, but splints can affect horses of any age.
Signs and diagnosis
Clinical signs vary in severity. Some horses show no evidence of pain or lameness, whereas others do appear lame, have soft tissue inflammation and pain on palpation.