Hoof Moisture
There are two types of hoof moisture. Systemic moisture is supplied by blood. Environmental moisture comes from outside the horse. Systemic moisture is increased by correct circulation and correct hydration. Environmental moisture is increased by freestanding water like dew, puddles, and wet mud. It is decreased by drying mud (it sucks out hoof moisture), standing in shavings or sand often, and some hoof dressings (those containing alcohol and petrolium).
Conformational Defects of the Limbs
In this conformation discussion 'inside' does not refer to inner structures but where a part of the horse deviates. 'Outside' does not refer to an exterior portion of the horse but to a part being pushed away from the horse.
Forelegs
Ideal foreleg: straight, all bones line up, straight movement, even weight distribution, correct shock absorbtion, and the angle of the pastern is about 50 degrees. Any misalignments increase stress on the limb and increase the risk that the horse could develope a lameness.
From the Front
Toed out: toes point out, increases stress on the inside and the risk of interference. The horse may wing in.
Toed in (pigion toed): toes point inward, increases stress on the outside. The horse may paddle (wing in).
Knock-knees: knees deviate inward toward the middle of the horse, increases stress on the inside of the knee.
Bowlegged: knees deviate outward, increases stress on the outside of the knee.
Base narrow: the space between a horse's forlegs decreases as we look from the chest to the hooves, the feet are too close together. This increases stress on the out side and because the feet aren't very far appart the horse is rather unstable and it takes more effort to stay in balance.
Base wide: legs are farther appart at the hooves than at the chest. It is a very balanced position except it increases stress on the outside of the leg.
From the Side
Standing under: horse always appears to be leaning forward over the chest because the shoulder blade and humerus are long with steep angles.
Camped out: horses forelegs extend in front of the horse because of a short shoulder blade and humerus with very sloping angles.
Calf knees (back at the knee): the knee is placed too far back putting stress on the back of the knee.
Buck knees (over at the knee): the knee is place too far forward. The tendons coming down behind and below the knee may appear to be pinched inward. It may appear that the horse is standing in front of the knee.
Steep pasterns: the angle is about 60 degrees, the pasterns are too vertical. This decreases shock absorbtion. Pasterns are generally too short. Steep pastern angles often mean steep shoulder angles.
Sloping pastern: angle is 45 degrees or less. This can occur through an injury (perhaps an injury to the suspensory ligament) or genetically. It increase shock absorbtion however it puts more stress on the tendons and ligaments. During fast movement and over even small jumps the fetlock may almost go down so far as to hit the ground which may result in injury. Sloping pasterns often mean sloping shoulder angle.
Hind Legs
Ideal hind leg: femur must deviate outward enough so the stifle joint isn't under the horse and so it won't hit the horse during movement. The point of the hock should turn in to the same degree as the stifle turns out, the toe should turn out to the same degree that the stifle turns in. Cannon bone is vertical.
From the Side
Short leg: the cannon bone is in front of a plumb line (imaginary line drawn from the point of the buttock to the ground) the leg is short. This is wanted in a racehorse because a short leg hits the ground more often, however it also decreases shock absorbtion.
Long leg: cannon falls in front of a plumb line. It increases the angles and therefor shock absorbtion but since the leg is so long it is hard to bring it under the body to allow for engagement.
Sickle hock: the cannon bone angle foreward from top to bottom. A horse is only truely sickle hocked when it is totally unable to stand with the cannon vertical. Any horse can appear sickle hocked if they stand wrong, but if they can stand correctly the horse is not sickle hocked.
From the back
Cowhock: The point of the hock points in more than the stifle turns out.
Bow leg: the point of the hock turns out more than the stifle.