Action: The movement of the horse's legs.
Ankle: The area that extends from the coronet to and including the fetlock.
Back at the Knee: A conformation fault in which the foreleg is bowed back at the knee. This fault is more serious than over at the knee because it places additional strain on the tendons running down the back of the lower leg and more concussive forces to the front of the knee. Also called "Calf-Kneed."
Bandy-legged: Condition in which the hocks turn outward. (Also called bow-hocks.) Opposite of cow-hocks.
Bog Spavin: Soft, synovial swelling seen on the high inside of the hock. Does not usually cause lameness, unlike regular spavin.
Bone: The ratio of the bone to the horse's weight. This measurement of the bone is taken around the leg, just below the knee or hock. This ratio determines the horse's ability to carry weight; therefore, a light-boned horse will be limited in his weight-carrying capacity.
Bowed Tendon: Strain of a tendon; usually refers to the superficial digital flexor tendon, which runs down the back of the lower leg.
Bow-hocks: Condition in which the hocks turn outwards. (Also called Bandy-legged.) The opposite of cow-hocks.
Brushing Boots: Item of horse equipment used to protect the horse's legs from injury due to brushing.
Brushing: Where the hoof or shoe hits the inside of the opposite leg, at or near the fetlock. Usually caused by poor conformation or action.
Buck-kneed: A conformation fault in which the foreleg bows forward at the knee. Also called Over at the Knee.
Calf-kneed: A conformation fault in which the foreleg is bowed back at the knee. This fault is more serious than over at the knee because it places additional strain on the tendons running down the back of the lower leg and more concussive forces to the front of the knee. Also called "Back at the Knee."
Cannon Bone: The long bone of the lower foreleg between the knee and the fetlock. Also called the "shin bone." On the hind leg, the corresponding bone is called the shank.
Capped Hocks: Swelling or puffiness on the point of the hock. Can be caused by a blow or injury, or may be caused by a horse lying down repeatedly in a stable with insufficient bedding.
Chestnuts: The horny growths on inside of horse's leg, either above the knee or below the hock; also called night eyes.
Coon Footed: A conformation fault in which the angle of the pastern becomes more horizontal and the fetlock drops.
Cow-hocks: Condition in which the hocks turn in, like those of a cow. Opposite of bow-hocks.
Cross-firing: Condition in which the hind foot strikes the opposite front leg or hoof.
Degenerative Arthritis: See degenerative joint disease (DJD).
Degenerative Joint Disease (DJD): Term for a group of disorders resulting in progressive deterioration of the articular cartilage of a joint, accompanied by bone proliferation around the joint margins and thickening of the soft tissues of the joint; also called degenerative arthritis.
Diagonals: The horse's legs move in pairs at the trot, called diagonals. The left diagonal is when the left foreleg and right hind leg move together, the right diagonal is when the right foreleg and the left hind leg move together.
Dipped Back: An unusually hollow back between the withers and the croup. Can occur as a result of aging. (See also Sway Back.)
Dishing: A faulty action, where the foot of the foreleg is thrown outward in a circular movement with each stride.
Ergot: Horny growth at the back of the fetlock joint.
Favor: To limp slightly.
Fetlock (Joint): The joint between the long cannon bone and the pastern bone.
Firing: Treatment in which the skin over a leg injury is burned with a hot iron to produce scar tissue.
Flat-footed: When the angle of the foot is noticeably less than 45 degrees.
Flexion: Describes the full bending of the joints. Veterinarians perform "flexion tests" when diagnosing lameness.
Flexor Tendon: Tendon at the back of the horse's leg that bends the joints below the knee backward.
Forearm: The upper part of the foreleg, above the knee.
Forging: A fault in a gait which occurs when a hind foot strikes the bottom of the front foot on the same side.
Gaskin: The lower part of the horse's thigh between the hock and stifle.
Go Short: To take short steps, indicative of lameness.
Grease: Inflammation of the skin at the back of the fetlock and pasterns.
Hock: Joint midway up the hind leg, responsible for providing most of the forward energy of the horse.
Hocks Well Let Down: Term used to indicate a horse that has short cannon bones (shanks) which is considered to be a good conformational trait giving the horse strength in the legs. Long cannons, on the other hand, are considered a conformational weakness.
Interference: Faulty gait in which a foot strikes the fetlock or cannon of the opposite foot; most often done by base-narrow, toe-wide, or splay-footed horses.
Joint Ill: Disease in foals caused by bacteria that enter the body through the navel, resulting in infection, which spreads to the joints and causes inflammation, pain, and heat.
Knock-Kneed: Conformation fault in which the knees point in toward each other.
Lameness: A defect detected when the animal favors the affected foot when moving or standing. The load on the ailing foot in action is eased and a characteristic bobbing of the head occurs as the affected foot strikes the ground.
Lateral Cartilages: Wings of cartilage attached to the coffin bone, within the foot.
Light of Bone: Insufficient bone below the knee to support the horse and rider's body weight without strain. Conformation fault.
Nerve Block: Diagnostic tool in which the veterinarian progressively blocks the nerves of the hoof and leg in order to determine the location of a lameness.
Open Behind: Faulty conformation in which the hocks are far apart and the feet close together.
Overreaching: Faulty gait in which the hind foot steps on the heel of the front foot on the same side. Occurs most commonly when the horse is galloping or jumping.
Paddling: Throwing the front feet outward as they are picked up; most common in toe-narrow or pigeon-toed horses.
Pastern: The sloping bone in the foot, which connects the hoof to the fetlock.
Pathological: A disease condition.
Pigeon-toed: Conformation fault in which the feet are turned inward.
Ringbone: Disorder characterized by new bone growth adjacent to either the pastern or coffin joints; caused by tearing of the ligaments that stabilize the joint. High ringbone describes bone growth around the pastern joint, while low ringbone describes bone growth around the coffin joint.
Scratches: Scabby, oozing skin inflammation on the back of the pasterns, just above the heel.
Shank Bone: Hind cannon bone.
Sickle Hocks: Hocks, which are bent, giving the hind leg the shape of a sickle, with the hind legs too far under the body.
Sound: Free from lameness or injury.
Spavin: Name given to degenerative arthritis of the lower joints of the hock, characterized by a bony swelling, which can be felt on the front and inside of the hock. See also bog spavin.
Splints: Injury to one or both of the metacarpal or splint bones, that lay on either side of the cannon bone. Stress or strain can cause the ligaments attaching these bones to the cannon bone to pull and tear, causing heat, swelling, and lameness. Eventually, additional bone is laid down on the site of the injury, leaving behind a bony swelling, called a splint.
Stringhalt: Condition characterized by the over-flexion of the hind legs, in which the leg often is jerked up toward the belly at each step.
Suspensory Ligament: Ligaments that run from below the knee or hock to below the fetlock helping to stabilize the fetlock and prevent over-extension.
Tied in Below the Knee: A conformation fault in which the circumference of the cannon bone directly below the knee is substantially less than that above the fetlock.
Unsoundness: Term used to describe any condition, or conformation fault that limits the horse's ability to perform his job. May include conditions of the muscles, bones, heart, lungs, or other organs.