An anatomical plane that is parallel to the ground. It can be at any level, through any structure.

Horn is the substance from which hooves, horns, finger and toe nails and the beaks of birds are made. Horn is created when the germinative (reproducing) cells of the epidermis undergo keratinisation (a.k.a. cornification), a process by which the cells are completely filled by keratin filaments to make them hard.

The process by which the germinal cells of the epidermis divide and are converted to horny tissue (cornification); this results in the growth of horn. The maximum rate of horn growth in hooves is approx. 8 mm per month (the hoof wall).

A type of cylindrical horn structure found in the horn of the hoof. It represents the horn that is grown from the epidermis of the papillae on the corium of the hoof wall and the sole. Microscopically a small medullary cavity is visible in the centre of the tubule - this is caused by the lack of germinative cells at the very tip of the papilla.

A type of horn which is extremely solid. The majority of the hoof capsule consists of hard horn (the stratum medium of the hoof wall as well as the sole), whereas the frog and the bulbs consist of soft horn.

Horn that retains a considerable degree of elasticity. The horn of the frog and the bulbs are examples of soft horn. Soft horn contains a higher percentage of water than hard horn.

A thickened area of skin as a result of increased pressure and wear, caused by a cornification of the epidermis in a location which would not usually be cornified.

A gaited horse refers to an individual or a breed of horse which exhibits an ambling gait (e.g. tölt, rack, running walk, foxtrot etc.). The horses are always capable of performing the basic gaits (walk, trot, canter and gallop) as well.

A horseshoe is a device attached to the ground facing (solar) side of the hoof designed to protect the horse's hoof from wear. Horseshoes are available in a large range of materials and styles, and the choice of what type to use depends on the type of work a horse is required to perform. Most horseshoes are made of metal (steel or aluminium) and are nailed onto the hoof wall. There are horseshoes made from other materials (synthetic materials or combinations of metal and synthetics), and other means by which they are attached (glue-on shoes).

Horseshoe nails are used to attach the horseshoe to the hoof. The nails have a unique form; the head is square or rectangular with a chamfered edge, the shaft or shank of the nail has a rectangular cross-section and the point is bevelled on one side. This facilitates the nail exiting the hoof wall at a certain height rather than remaining within the wall when it is driven in.