Asymmetric loading is seen when during movement, the weight of the horse is distributed unevenly on the bearing edge of the hoof; the lateral or medial wall is loaded to a greater extent (i.e., bears more of the horse's weight) than the other wall. This uneven loading is more common in the hind limb and is usually due to conformational deficiencies such as bow-leggedness. It can lead to changes in the shape of the hoof capsule: the side subjected to more load becomes steeper and shorter, while the less loaded side becomes longer and tends to flare.

The line dividing the solar aspect of the hoof into two halves running from dorsal to palmar/plantar in the sagittal plane.

A hoof in which the hoof capsule, as a whole or in parts is contracted reative to a 'normal' hoof. The hoof walls in the quarter and heel region are more upright than usual. In extreme cases, the width of the hoof is narrower at the bearing edge than it is at the coronet. Soft tissue within the hoof capsule is under increased pressure.

An asymmetrichoof. From the solar aspect, the halves of the hoof are unequal in size and shape, when seen from the front of the back the slope of the medial and lateralhoof walls is different.

To go over the freshly shod hoof with a fine rasp or sanding block to remove any sharp edges or protruding fragments of horn after nailing and clenching.

To go over the freshly shod hoof with a fine rasp or sanding block to remove any sharp edges or protruding fragments of horn after nailing and clenching.

The hoof of the hindlimb. The angle of the dorsal hoof wall is usually between 50-58° and the shape of the hoof from the solar aspect is more oval than the hoof of the forelimb.

A horny structure protecting the distal end of the digits of all ungulates. Equivalent to the human finger or toe nail. The hoof consists of a horny hoof capsule, the sensitive dermis or corium and the subcutis which surround the distal digital structures including the distal part of the short pastern bone (middle phalanx), coffin bone (distal phalanx), navicular bone and associated soft tissue structures.

An infection of the soft tissues underneath the hoof capsule resulting in the formation of pus. As the formation of pus results in a significant build-up of pressure underneath the hoof capsule, this is an extremely painful condition that can cause non-weightbearing lameness. The colour of the pus can give some indication of the depth of the abscess: superficial abscesses involving predominantly keratinised cells produce dark pus, if deeper structures are involved (corium, subcutis, periosteum or even bone), the pus is pale yellow/grey/pink in colour.

The angle between the dorsal hoof wall and the bearing edge (or ground surface). In warmbloods the hoof angle ranges from 45-55° in the front hooves, 50-58° in the hind hooves. Thoroughbreds have a hoof angle that is on average 2.8° less than warmbloods.

The axis that best corresponds to the slope of the dorsal hoof wall. If the dorsal hoof wall is convex or concave, it corresponds to the slope of the upper (proximal) third of the wall. Idealy it is parallel to the pastern axis, resulting in a straight hoof-pastern axis.  The angle between the hoof axis and the ground is known as the hoof angle.

A bandage that covers the entire hoof up to mid pastern or fetlock height. It is used to cushion a sore hoof, reposition a laminitic hoof (in conjunction with some form of frog and heel support) and most frequently to protect any exposed sensitive tissue (e.g. as results through injury or opening of a hoof abscess) from dirt or moisture.

A type of boot made of plastic or leather which can be pulled over and attached to the hoof with straps to provide temporary hoof protection.

The entirety of the horny structures of the hoof including the hoof wall, the bars, the sole and the frog.

Hoof care includes regular cleaning of a hoof, checking for injury and correcting any deviations in shape. These tasks are essential contributions to the health and physiological functioning of a hoof.

A crack i.e. disruption in structure of the horn capsule that is defined according to its location (toe, quarters, heels or sole) its depth (superficial or deep) and its type (vertical or horizontal). Vertical cracks of the wall may originate from the bearing edge (grass cracks) or from the coronary band (sand cracks), they are parallel to the horn tubules and may extend partially or completely up/down the wall.

The layer of sensitive tissue between the horn building epidermis and the subcutaneous tissue or bone. It contains blood vessels and nerves and supplies the epidermis with all the nutrients it needs for the production of horn. The dermis of the hoof has distinct modifications depending on the region of the hoof.

The terms dermis and corium are used synonymously and are encountered with equal frequency.

A device used to measure the angle of the dorsal hoof wall.

The hoof mechanism refers to the changes in shape of the horn capsule during the loading and unloading cycle of the hoof during movement. This change in shape is due to the elasticity of the horn capsule and is greater in areas where the hoof wall is thinner i.e. towards the heels (heel expansion).

Applied to the dorsal hoof wall to give the hoof a shiny appearance. Protects the hoof from moisture.

A layer of leather, plastic, rubber or felt that is inserted between the hoof and the horseshoe. It may cover the whole of the sole (full pad), part of the sole or be limited to the region just underneath the shoe (rim pad). The purpose of pads is to protect the structures of the hoof (wall, sole, frog etc.) or dampen the shock of impact. 

The imaginary line drawn through the centre of the three phalanges. From the front (dorsal) or back (palmar/plantar) aspect, the line should equally bisect the hoof and pastern and be perpendicular to the ground. From the side, the line should be straight and parallel to the line of the dorsal hoof wall, if this axis is not straight, one differentiates between a broken forward phalangeal axis or a broken back phalangeal axis (or HPA).

A patch, generally made of fibre-glass cloth that is applied to a deep hoof crack to stabilise the crack, prevent further development and promote healing (growing out of the crack). The patch can either be glued on with strong 2 component adhesives or held in place by several screws inserted into the insensitive hoof wall. A patch can also be made of a metal plate held in place by screws.

A hook like tool used on a daily basis to remove dirt from the clefts of the frog and the sole.

A synthetic mass that is malleable when warm and solid when cold that is applied to the exposed sole of the shod hoof. Its purpose is to prevent snow from balling-up under the sole.

A ring shaped prominence on the surface of the hoof wall. There may be several, giving a ridged appearance (the ridges are more or less parallel to the coronary band). These rings represent changes in rate and quality of horn growth and may be due to seasonal or dietary factors or represent health issues (e.g. laminitis). Seasonal or dietary rings are parallel to the coronary band throughout, health related changes may diverge, usually at the heel.

A complete avulsion of the hoof capsule due to a loss of connection between the hoof capsule and the distal phalanx. This condition can be caused by severe inflammation (laminitis) or a complete loss of bloodcirculation to the foot (severe pastern rope injury).

An examination that is used to test the sensitivity of the soft tissue structures within the hoof capsule. Pressure is applied  with the hoof testers to various parts of the hoof capsule and the pain response is assessed. This is a routine part of every lameness examination.

A set of pincers with wide opening jaws and slightly serrated faces. Local pressure is applied on the hoof by closing the pincers with one jaw on the sole/frog and the other on the hoof wall. The hoof testers are moved systematically  around the hoof wall and sole to check for a pain response to pressure. A positive pain response (the horse abruptly pulls away the hoof) indicates the presence of inflammation.

A layer of liquid varnish that is applied to the hoof wall to prevent the transfer of moisture between the hoof wall and the environment.

The section of hoof that forms the main supporting stucture that includes the walls of the toe, the quarters, the heels and the bars. In cross-section it consists of the stratum externum (perioplic horn), medium and internum (lamellar horn).

A loss of continuity of the horn wall originating from the bearing edge characterised by a loss of substance.The damage may start as a grass crack and progress to a defect or it may be due to a trauma such the loss of a shoe. If the damage is limited to the outer layers of the hoof wall this results in a frayed appreance of the hoof wall, damage to the entire thickness of the wall leads to a 'gap' in the distal border. The cause of this type of damage is frequently the result of an error in nailing (too large or misplaced nails) or an excessively long shoeing interval.

A hoof which is significantly longer than it is wide. Horses with this type of hoof may be known as hoof bound.

A horse's foot without a shoe in place

The moment where the hoof makes contact with the ground at the end of the swing phase representing the beginning of the stance phase. Most horses land flat (all parts of the hoof simultaneously) or fractionally heel first. 

A low heeled hoof appears flat: the hoof angle is shallow, the dorsal wall is often long, the sole is barely arched or flat and the heels are under-run or collapsed. This type of hoof frequently results in a broken back hoof-pastern axis.

The morphological appearance of white line disease - the hoof wall is separated from the sole horn in the region of the white line (extending up to the level of the terminal papilla of the stratum internum). If the damage extends further up the hoof wall it is termed seedy toe or hollow hoof wall.

A hoof that has a pattern of rings on its hoof wall. Their formation is due to changes in speed and sometimes direction of horn growth. The rings may be parallel to the coronary band, in which case they are generally due to changes in diet. Rings that diverge towards the quarters and heels are generally due to the changes in horn growth rate seen in horses with chronic laminitis.

An axis which runs through the centre of the hoof and splits it into two more or less equal halves. Can apply to the frontal or solar view.

The solar aspect of the hoof including the bearing edge, the bars, the sole and the frog.

The suspensory apparatus of the hoof is the mechanism by which the hoof wall is attached to the distal phalanx (coffin bone); as the sole of the hoof does not rest on the ground (concavity of the sole), the bone is effectively 'suspended' from the inside of the hoof capsule. Structures involved in this mechanism include the tight bond at the dermal-epidermal junction in stratum internum (junction of the sensitive and insensitive lamella) and the deep digital flexor tendon.

Asymmetric loading is seen when during movement, the weight of the horse is distributed unevenly on the bearing edge of the hoof; the lateral or medial wall is loaded to a greater extent (i.e., bears more of the horse's weight) than the other wall. This uneven loading is more common in the hind limb and is usually due to conformational deficiencies such as bow-leggedness. It can lead to changes in the shape of the hoof capsule: the side subjected to more load becomes steeper and shorter, while the less loaded side becomes longer and tends to flare.

An undermined hoof wall is a separation between layers of the hoof wall, most frequently of the inner-most layer (between the stratum internum and the stratum medium) of the hoof wall. The sensitive lamina remain covered by a thin layer of horn. The ensuing cavity is usually filled with a crumbling type of horn caused by bacterial and/or fungal digestion of the tubular and lamellar horn. The lesions may extend from the bearing surface up to the coronary band.

The hoof of the forelimb. The hoof angle (angle of the dorsal hoof wall to the ground) is usually between 45° and 55°, depending on breed and individual conformation. Warmbloods generally have a slightly higher hoof angle in the fore feet than Thoroughbreds. The shape of the hoof when viewed from the sole is usually rounder than the hind foot, although it should not be wider then it is long.

Flat, wing-like structures made from fibro-cartilage that are attached to the palmar/plantar processes of the distal phalanx (coffin bone) and extend proximaly to above the level of the hoof capsule. They can be palpated proximaly to the coronary band in the lateral and medialpalmar/plantar region of the pastern where they should yield to gentle pressure. The cartilage can ossify in part or completely (sidebone).

A farriers scalpel, the drawing knife is used to pare the horn of the frog and the sole. The knife has a slightly curved one-sided blade which terminates in a sharp turn, at right angles to the flat side of the blade.

A tool used to shorten the hoof wall (bearing edge).

There are two types, nippers with two sharp jaws which meet perfectly, cutters with one sharp jaw which is overlapped by a blunt jaw, 

The presence of bony tissue (visible on a radiograph) in the collateral cartilage of the hoof. In some horses, sidebone is a normal development with increasing age (most frequently observed in cobs and heavy horse breeds). If seen in younger horses, the causes (apart from genetic) include conformational problems of the limb or the hoof, repeated trauma or work on hard ground and inappropriate shoeing. Sidebones are usually painful whilst forming and may then settle to cause virtually no discomfort at all. However large sidebones may interfere with associated tissue and cause discomfort.

A tool with sharp convex jaws that are used to cut indentations in the hoof wall, e.g. for setting in clips.

A shoeing aid consisting of a tripod or weighted circular base attached to a hoof rest. The solar surface of the hoof is rested on the stand, enabling procedures such as dressing of the wall or clenching to be carried out without having to hold the hoof.

The hoof wall in the region of the toe.