What is a Splint?

The word "splint" is a term used for a protruding, hard bump that forms between the splint and cannon bone on either the inside or outside of a horse's lower leg. Splints are more likely to occur on a front leg than on a hind leg, and usually happen in younger, developing horses from an internal strain. A splint can also occur because of an exterior strike or bruise, such as a horse kicking itself with one of its feet.

The strike causes bruising to a small ligament that connects one of the leg's two splint bones to the cannon bone. Initially, the lump feels warm or hot to the touch and can cause very mild, hardly noticeable to moderate lameness.

With rest, the site heals by building up a calcium deposit that essentially bonds the splint bone to the cannon bone. Once a splint heals, the new boney protuberance is quite hard and cold to the touch. Horses do not usually experience pain from a cold, or healed, splint.