Evaluating Horse Conformation Pt 5

For example, base narrow horses are predisposed to landing on the outside of their hoof wall. This increase in pressure on the outside of the hoof wall can lead to conditions such as ringbone, sidebone and heel bruising. At the opposite extreme, base wide horses tend to toe out. This causes weight to be distributed more on the inside of the horse's hoof and also predisposes them to ringbone and sidebone. Deviations of the knee (bowlegs, knock knees, etc.) cause increased strain on this joint and the ligaments and tendons attached to it. Knock knees (knees set to the inside) tend to also be associated with pigeon toes and therefore additionally have rotation of either the cannon bone, fetlock or pastern. This causes extreme pressure to be placed on the point of rotation. All of these deviations cause an unequal line of concussion. The concussion from every stride the horse takes causes an impact to travel up the leg unequally. The area that absorbs more of the concussion is more likely to be damaged.

When examining the horse's legs, the horse should also be viewed from the side (Figure 13). A straight line should be able to be drawn from the center of the scapula through the front edge of the knee and bisect the hoof. Structural deviations that may be observed are "camping out" and "camping under." A horse that is "camped out" will stand with its legs too far in front of it, causing excessive pressure to be placed on the hooves as well as the knee and fetlock joints. These joints must almost bend backwards for the horse to stand in this position. This stance can be due to conformational defects or sometimes are an indication of hoof pain, such as navicular. The horse that is "camped under" will stand with its legs too far underneath it, causing increased strain to be placed on the ligaments and tendons of the leg. It also causes the horse to carry too much weight on its front end, which can cause lameness due to stress and also causes the horse to have a short, choppy stride and potential stumbling. It is important to recognize that the way the horse is standing greatly influences this view from the side. Be sure the horse is standing naturally and squarely before concluding that it is either naturally camped out or camped under. Many horses will stand this way simply because they are not correctly stood up by the handler.

Two other conditions that may be observed from the side of the horse are calf knees (back at the knee) and buck knees ("knee sprung" or over at the knees). If the line does not bisect the knee but instead is to the front of the knee (i.e., the knee looks as if it is bending the wrong way), the horse is considered calf kneed. This is typically considered to be the more problematic of the two faults since it causes excessive strain on the back ligaments and tendons of the leg as well as pressure on the front of the carpal joint, making the horse more prone to carpal arthrosis. If the line is in back of the knee (i.e., the knee looks like it is bent even when the horse is fully bearing weight on the leg), the horse is considered "over at the knees" or "buck kneed," a condition that also distributes pressure unequally over the leg.

Hind leg conformation

The horse's hind legs should also be examined for structural deviations by viewing them both from the side and from behind the horse. When facing the hindquarters of the horse from behind (standing behind the horse looking at its tail) one should be able to draw a straight line from the horse's buttock through both its hock and fetlock (Figure 14). The hooves on the back leg will not be as straight as the front hooves; it is normal for these to point slightly outward.