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The set of teeth develop in the embryo and emerge shortly after birth. They are eventually lost and replaced by the permanent teeth. In horses the complete set of deciduous teeth are present 6-9 months after birth and contains 24-28 teeth (12 incisors, 12 molars, occasionally 4 canines).
A distension of the subtendinous calcaneal bursa (between the calcaneus and the end of the achilles tendon (gastrocnemius tendon).
The tendon connecting the deep digital flexor muscle to the palmar/plantar surface of the distal phalanx. It lies underneath the superficial digital flexor tendon (SDFT) along the back of the cannon and passes through the SDFT where this inserts on the middle phalanx.
A disease or condition that gets steadily worse and is characterised by a gradual deterioration of the function of a body tissue or organ.
Caps are the remnants of deciduous teeth that fail to be shed after erruption of the permanent teeth. They may lead to pain and difficulties in chewing.
A morphological feature of horses' teeth. The dental cup is an oblong hollow formed by the the central enamel, which is filled with cementum (a softer material) and appears darker than the neighbouring surface of the tooth. The cups decrease in depth with increasing wear of the teeth and eventually disappear altogether. The order in which they disappear from the incisor teeth is used as an indicator of the horse's age.
The height of the thorax as measured from the point of the withers (spinous process of the 5th thoracic vertebra) to the sternum.
A leaf-like structure that is a feature of the lamellar dermis that covers the parietal surface of the coffin bone. There are approximately 600 primary lamellae running in a proximo-distal direction down the entire dorsal surface of the distal phalanx. The lamella project at right angles to the surface of the bone and are perpendicular to the papilla of the coronary dermis. Each primary lamella is covered in 100-200 secondary lamellae which also extend in a proximo distal direction and serve to increase the surface area of the dermis. The horn covering the lamellar dermis is the inner most layer of the hoof wall (stratum lamellatum).
A disease of the skin which occurs as a result of continuous exposure to moisture, for example on the back and croup or horses kept outside in wet conditions or on the front of the cannon bones in horses which have their legs hosed down daily. The symptoms usually start as tufts of hair which are easily pulled out and progress to scabs and pustules over a larger area. The disease is caused by a bacterium called Dermatophilus congolensis, which is frequently present on the skin of healthy horses and is easily transmittable from horse to horse as well as from horse to humans. To invade the skin, the bacterium requires small wounds or moisture softened skin.
A layer of sensitive tissue between the epidermis (the outermost layer of the skin) and the subcutaneous tissue. The structural components of the dermis are collagen and elastic fibres. It is well supplied with blood vessels and nerve endings. The dermis of the hoof is frequently known as the corium.
Surgical transection of a ligament as a form of treatment for certain orthopaedic diseases. Frequently encountered examples include desmotomy of the inferior check ligament as a treatment for club foot or of the medial patellar ligament as a treatment for pathological upwards fixation of the patella.
The shaft of any long bone between the upper and lower metaphysis (the neck of the bone). The shaft typically consists of a hollow tube of compact bone with a central cavity. The central cavity containes red or yellow bone marrow.
A diastema is a gap between teeth not caused by the loss of a tooth. The horse has a large physiological diastema between the canine and the first premolar tooth. This is level with the corner of the mouth and enables the bit to lie in the mouth without contact to the teeth.
A medical term that refers to a disease condition that is widespread or generalised. The opposite of focal. An example is a diffuse aseptic pododermatitis, which is the medically correct term for a non-infectious, widespread inflammation of the dermis of the hoof.
The distal section of the horse's limb, comprising the three phalanges: the proximal phalanx (long pastern bone), the medial phalanx (short pastern bone) and the distal phalanx (coffin bone), as well as the distal sesamoid bone (navicular bone).
A wedge shaped pad of fibrous connective tissue that lies beween the corium of the frog and the end of the deep digital flexor tendon. Laterally and medially it is bordered by the ungular (co-lateral) cartilages and to the back (palmar/plantar aspect) it lies directly underneath the corium and epidermis of the bulbs. It contains a high proportion of collagenous and elastic fibres, along with fat cells, islets of cartilage and relatively few blood vessels.
The fibrous, elastic subcutaneous tissue that makes up the digital cushion and extends caudally to give the bulbs of the heel their characteristic rounded shape.
The fibrous, elastic subcutaneous tissue that represents the portion of the digital cushion underneath the frog where it mimics the frog's shape.
A provocation test used during a lameness examination. The horse's distallimb is artificially hyperextended by placing the hoof on the end of a board and lifting the other end. This will put pressure on the palmar region of the foot by increasing the tension in the deep flexor tendon, this in turn, will accentuate pain in this region of the foot and will cause the horse to hop off the board. The test is more difficult to interpret than a flexion test and must be evaluated carefully; frequently a left-right comparison is useful.
The tendon responsible for the extension of the distallimb (fetlock, pastern and coffin joints. In the forelimb the common digital extensor tendon has four origins on the humerus, radius, ulna and the fascia of the forearm, it inserts on the dorsal aspect of the proximal and middle phalanx and finally on the extensor process of the distal phalanx. In the hindlimb, the long digital extensor originates on the femur and has the same insertions as the common digital extensor in the forelimb.
A large tendon sheath which envelopes the superficial and deep digital flexor tendons where they pass over the palmar/plantar aspect of the fetlock joint. Its proximal margin is several cm above the fetlock joint, its distal margin slightly below the level of the proximal interphalangeal joint.
A regional nerve block used during lameness examination. The nerves blocked are the medial and lateral branches of the palmar/plantardigital nerve. The block can be applied at various positions on the pastern; the structures desensitised depend on the exact placement of the anaesthetic. Most frequently used sites of injection
1. Applied just above the collateral cartilages
2. At mid pastern, just behind the palpable vascular bundle.
A drug/medication that is able to permeate skin (transdermal absorption), increases blood flow locally and has an anti-inflammatory effect.
An extinct ancestor of modern horses, Dinohippus emerged ~12 mya from late Merychippus species. It was a one-toed grazer and its skull, teeth and limbs were already very similar to our modern horse. It appears that the passive stay apparatus, which allows horses to stand without muscle power, first appeared in Dinohippus.
During the late Pliocene, Dinohippus was the most widely distributed horse in North America and it is assumed to be the direct ancestor of the genus Equus.
Measures that are taken to destroy, remove or inactivate potentially harmful microorganisms to reduce the likelyhood of infection. Disinfection requires the use of a disinfectant or antiseptic chemical.
An anatomical directional term meaning further away from a point of reference. When refering to the horse it generally means further away from the trunk.
A saddle joint between the distal phalanx (coffin bone) and the middle phalanx (short pastern bone).
The most distal of the phalanges, located within the hoof capsule (hence the name 'coffin' bone). As it is in the horse's foot, the term pedal bone is also used interchangeably. A further term for the same bone is 'P3', relating to its position as the third phalanx.
The bone is irregularly shaped with a convexdorsal (parietal) surface, a concavesolar surface and an articular surface where it forms a joint with the middle phalanx (short pastern bone).
The ligament between the navicular bone and the distal phalanx (coffin bone). In contrast to most ligaments which exist in pairs (one on the medial and one on the lateral side of the limb), there is only one of these ligaments in each limb, hence its common name 'impar' ligament.
The ligament between the navicular bone and the distal phalanx (coffin bone).
Going in a different direction or departing from a set course.
The dock refers to the body of the tail as a whole, including the vertebrae, the skin and the hair follicles. The base of the tail refers to its point of attachment to the body.
Domestication is the process whereby a population of animals or plants, through a process of artificial selection, is changed at the genetic level, accentuating traits desired by humans. The process of artificial selection is the equivalent of natural selection with the specific traits of animals used for breeding selected for desirability rather than survival (e.g. speed in racehorses or muscle mass in beef cattle).
Species of the Equus genus that include the domestic donkey (Equus africanus), which is a direct descendant of the African wild ass. The donkey is the original beast of burden and is still used as a working animal in large parts of the world. There are over 180 different breeds of donkey, most of which are threatened by extinction (as are most of their wild couterparts).
The use of performance enhancing drugs or methods with the aim of improving athletic performance. Doping can be harmful to an individuals health and its use, particularly in animals, violates the ethical principles of fair competition and animal welfare.
An anatomical term meaning towards the upper plane
A notch found in the middle of the solar margin of the distal phalanx. Is often associated with a slight widening of the white line in the centre of the toe. It is not, as is often erroneously assumed due to the pressure of a toeclip.
A horse used to pull a load. The draught horse used to be a working horse used in many industries such as agriculture, transport, mining or forestry. These days the draught horse is more likely to be used as a carriage horse for leisure or sporting purposes.
The process of drawing out a section of metal from the outer edge of the shoe to forge a clip.
An equestrian sport where a horse is required to perform a series of lessons in an arena with the purpose of demonstrating its natural athletic ability and willingness to perform.
Dressage is an FEI and an Olympic discipline.
A light hammer with a flat face used for driving the horseshoe nails through the shoe into the hoof. There are two versions of this hammer, one with a rounded end opposite the face, another with a pair of claws opposing the face which can be used to wring off the ends of nails or remove partially inserted nails.