Lameness (equine)
Encyclopedia
Lameness in horse
Horse
The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...

s and other equidae
Equidae
Equidae is the taxonomic family of horses and related animals, including the extant horses, donkeys, and zebras, and many other species known only from fossils. All extant species are in the genus Equus...

 is a term used to refer to any number of conditions where the animal fails to travel in a regular and sound manner on all four feet. There are many causes of lameness, which can be broadly grouped into the following categories:
  • Laminitis
    Laminitis
    Laminitis is a disease that affects the feet of ungulates. It is best known in horses and cattle. Symptoms include lameness, and increased temperature in the hooves...

     or other inflammatory diseases of the hoof
  • Injury to bone, muscle, tendons or ligaments, ranging from pulled muscles to broken bones
    Bone fracture
    A bone fracture is a medical condition in which there is a break in the continuity of the bone...

    .
  • Complications of inflammation or stocking up
    Stocking up
    Stocking up, also known as Filling up or Filled legs refers to a condition in horses caused when fluid builds up and swells the leg. Sometimes it is linked to lameness and other times it is purely an aesthetic problem. Fluid buildup can be caused by dozens of different things, though often is...

     related to overwork
  • Injury induced by compensation for strain or pain in other parts of the body, particularly the back
    Back (horse)
    The back describes the area of horse anatomy where the saddle goes, and in popular usage extends to include the loin or lumbar region behind the thoracic vertebrae that also is crucial to a horse's weight-carrying ability. These two sections of the vertebral column beginning at the withers, the...

  • Neurological disorders, such as Wobbler's syndrome
  • Swelling and inflammation linked to infection, such as cellulitis
    Cellulitis
    Cellulitis is a diffuse inflammation of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin. Cellulitis can be caused by normal skin flora or by exogenous bacteria, and often occurs where the skin has previously been broken: cracks in the skin, cuts, blisters,...

     or thrush
    Thrush (horse)
    Thrush is a very common bacterial infection that occurs on the hoof of a horse, specifically in the region of the frog. The bacteria occur naturally in the animal's environment—especially in wet, muddy, or unsanitary conditions, such as an unclean stall—and grow best with low oxygen...

    .
  • Hoof
    Horse hoof
    A horse hoof is a structure surrounding the distal phalanx of the 3rd digit of each of the four limbs of Equus species, which is covered by complex soft tissue and keratinised structures...

     problems, including injury, disease and poor farrier
    Farrier
    A farrier is a specialist in equine hoof care, including the trimming and balancing of horses' hooves and the placing of shoes on their hooves...

     work
  • Diseases affecting connective tissue, such as Equine Exertional Rhabdomyolysis
    Equine Exertional Rhabdomyolysis
    Equine exertional rhabdomyolysis is a syndrome that damages the muscle tissue in horses...

     and HYPP
  • Conformation defect leading to stress or injury, such as cow-hocked
    Cow-hocked
    Cow-hocked is the condition in a livestock animal where the back leg joints of the animal are set incorrectly. This term is used to describe when the back 'knee' on an animal is set inward, resulting in a splayed look in the back legs. This can result in the uneven wearing of hooves, which can end...

     or sickle-hocked
    Sickle-hocked
    Sickle-hocked is the technical term used to describe a specific type of incorrect leg structure in animals. The back leg joints of an animal, usually a horse or other equine mammal, are set with too much angle, resulting in the hock also being excessively angled. This can result in uneven hoof...

     conformation.


Diagnosing and treating lameness

Lameness severity is typically evaluated on a scale of 1 to 5, with higher numbers indicating a more significant degree of impairment. A 1 rating suggests a horse with a minor gait
Horse gait
Horse gaits are the various ways in which a horse can move, either naturally or as a result of specialized training by humans.-Classification:...

 deficit, a 5 is "broken-legged" lame, indicating that the horse will not put weight on the affected leg. Initial assessment may include a visual check for outward injuries such as cuts or swelling, observation of a horse as it travels at different gaits
Horse gait
Horse gaits are the various ways in which a horse can move, either naturally or as a result of specialized training by humans.-Classification:...

, particularly the walk and trot
Trot (horse gait)
The trot is a two-beat diagonal gait of the horse, where the diagonal pairs of legs move forward at the same time. There is a moment of suspension between each beat....

. Flexion test
Flexion test
A flexion test is a veterinary procedure performed on a horse, generally during a prepurchase or a lameness exam. The animal's leg is held in a flexed position for 30 seconds to up to 3 minutes , and then the horse is immediately trotted off and its gait is analyzed for abnormalities and uneveness...

s may also be performed, and hooves will be checked for signs of injury.

After the initial assessment, a typical procedure is to perform regional limb anesthesia (nerve blocks) to help to pinpoint the area affected. Once the causative area is determined, then radiographs or ultrasound
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...

 are performed to determine which particular structures are involved. More advanced imaging techniques include scintigraphy
Scintigraphy
Scintigraphy is a form of diagnostic test used in nuclear medicine, wherein radioisotopes are taken internally, and the emitted radiation is captured by external detectors to form two-dimensional images...

, computed tomography
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...

, veterinary thermal imaging and MRI.

Treatment varies depending on the condition diagnosed, but at a minimum includes rest, appropriate medication and other supportive therapies. Consultation with a veterinarian
Veterinarian
A veterinary physician, colloquially called a vet, shortened from veterinarian or veterinary surgeon , is a professional who treats disease, disorder and injury in animals....

 is generally recommended, even for mild cases, as some types of mild lameness may worsen if not properly diagnosed and treated.

An important component of an equine prepurchase exam
Equine prepurchase exam
When buying a horse, many buyers ask for an equine prepurchase exam. This serves to identify any preexisting problems which may hinder a horse’s future performance and reduce buyer risk...

 is a thorough lameness examination to rule out existing unsoundness.

Types of lameness

There are dozens of different types of lameness in horses. In addition, many conditions sometimes, though not always, have lameness as a symptom. Finally, there are a number of permanent blemishes that indicate that a horse has been lame in the past or has been subjected to strain that may lead to lameness in the future. These assorted conditions include:
  • Bog spavin
    Bog spavin
    Bog Spavin is a swelling of the tibiotarsal joint of the horse's hock which, in itself, does not cause lameness. The joint becomes distended by excess synovial fluid and/or thickened synovial tissue bringing about a soft, fluctuant swelling on the front of the joint, as well as in the medial and...

  • Bone spavin
    Bone spavin
    Bone spavin is a bony growth within the lower hock joint of horse or cattle. It is caused by osteoarthritis, and the degree of lameness that results can be serious enough to end a horse's competitive career.-Description of bone spavin:...

     - A bone spavin is the inflammation of bones that are between the inside of the hock joint and is extremely painful. It is caused by pounding on hard surfaces, sliding, roping, reining
    Reining
    Reining is a western riding competition for horses where the riders guide the horses through a precise pattern of circles, spins, and stops. All work is done at the lope and gallop; the fastest of the horse gaits...

    , and poor conformation. A jack spavin is a bony growth that irritates tendons under the inside of the hock. When the hock is flexed or bent there is much pain. The causes are from a hit to the joint, stress, trauma, and poor conformation. A knee spavin is a bony growth at the back of the inner side of the knee and is not very common. Joint stress and trauma are the causes of this.
  • Bowed tendon
    Bowed tendon
    Tendinitis/tendonitis is inflammation of a tendon. Many times, the tendon tissue is torn. A bowed tendon is a horseman's term for a tendon after a horse has sustained an injury that caused the tendon fibers to be torn, and then healed with "bowed" appearance.-Description of a Tendinitis in...

     - Bowed tendons are the inflammation or the rupture of the sheath of the tendon from the knee to the fetlock. The tendon can be the deep flexor tendon or the superficial flexor tendon and occurs in front legs. Severe trauma and over extension, a short warm up, fatigue, or a hit are the causes of a bowed tendon.
  • Capped joint - A capped hock is the swelling of the point of the hock and is caused by a hit to the area, the kicking of the wall, and lying on hard surfaces. A capped knee is the swelling and bruising of the knee and the tendons on the knee. This can be caused by a fall, banning, over work, and poor conformation. When the capsule of the knee is involved, fluid can leak into the area.
  • Curb
    Curb (horse)
    Curb is defined in older literature as enlargement secondary to inflammation and thickening of the long plantar ligament in horses. However, with the widespread use of diagnostic ultrasonography in equine medicine, curb has been redefined as a collection of soft tissue injuries of the distal...

     - Curbs are the inflammation of the upper rear of the cannon bone, below the point of the hock. Curbs can be caused by a hit to the area, kicking of a wall, or a violent extension of the plantar ligament.
  • Laminitis
    Laminitis
    Laminitis is a disease that affects the feet of ungulates. It is best known in horses and cattle. Symptoms include lameness, and increased temperature in the hooves...

     - Laminitis is the vascular disease, causing ischemia
    Ischemia
    In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...

     or homeostasis
    Homeostasis
    Homeostasis is the property of a system that regulates its internal environment and tends to maintain a stable, constant condition of properties like temperature or pH...

    . It affects the inside of the lamina where it becomes inflamed and obstructs with the bone bond. Symptoms of this are lameness, elevated temperature, breathing, and plus rate, pain in the toe, and depression in the skin near the wall of the hoof. The causes could be from a pre-existing illness, like Cushing's syndrome
    Cushing's syndrome
    Cushing's syndrome is a hormone disorder caused by high levels of cortisol in the blood. This can be caused by taking glucocorticoid drugs, or by tumors that produce cortisol or adrenocorticotropic hormone or CRH...

    , excess cards and weight, stress, long transportation, excess work on a hard surface, black walnut
    Black Walnut
    Juglans nigra, the Eastern Black walnut, is a species of flowering tree in the hickory family, Juglandaceae, that is native to eastern North America. It grows mostly in riparian zones, from southern Ontario, west to southeast South Dakota, south to Georgia, northern Florida and southwest to central...

     bedding, drinking when overheated, and insulin resistance. Laminitis can spread to all four legs and can be seen twenty four to seventy two hours after the incident. When Laminitis is chronic there is the displacement of the distal phalanx with no activity in the laminar necrosis
    Necrosis
    Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...

    . The growth of the dorsal lamina in the hoof becomes abnormal. The treatment is to be off the feet as much as possible, dietary restrictions, administering fluids and medicine, and soft bedding. Magnetic hoof pads can be used to increase circulation and relieve pain. Foundering, which can result from laminitis, is when the coffin bone become detached, rotates, or sinks. The horse usually shifts its weight to the back legs with the front extended.
  • Navicular Disease
    Navicular Disease
    Navicular Disease is a soundness problem in horses, more accurately called "navicular syndrome" as opposed to "disease." It most commonly describes an inflammation or degeneration of the navicular bone and its surrounding tissues, usually on the front feet...

  • Osselet
    Osselet
    -Location:Osselets usually occurs in the front legs of the horse, because there is more strain and concussion on the fetlock there than in the hind legs. The arthritis will occur at the joint between the cannon bone and large pastern bone, at the front of the fetlock.-Causes and...

    s - Green osselets is the inflammation of the joint capsule
    Joint capsule
    An articular capsule is an envelope surrounding a synovial joint.-Layers:Each capsule consists of two layers:* an outer layer composed of avascular white fibrous tissue...

     in the front of the fetlock
    Fetlock
    Fetlock is the common name for the metacarpophalangeal and metatarsophalangeal joints of horses, large animals, and sometimes dogs. It is formed by the junction of the third metacarpal or metatarsal bones proximad and the proximal phalanx distad...

    . It is caused by too much racing
    Horse racing
    Horse racing is an equestrian sport that has a long history. Archaeological records indicate that horse racing occurred in ancient Babylon, Syria, and Egypt. Both chariot and mounted horse racing were events in the ancient Greek Olympics by 648 BC...

     at a young age. True osselets is a bony growth at the front of the fetlock joint and is the late stage of green osselets, which was not allowed to heal.
  • Ringbone
    Ringbone
    Ringbone is exostosis in the pastern or coffin joint of a horse. In severe cases, the growth can encircle the bones, giving ringbone its name...

  • Sesamoiditis
    Sesamoiditis
    Sesamoiditis is inflammation of the sesamoid bones. In humans it occurs on the bottom of the foot, just behind the large toe. There are normally two sesamoid bones on each foot; sometimes sesamoids can be bipartite, which means they each comprise two separate pieces. The sesamoids are roughly the...

     - Sesamoiditis is the inflammation of the bone above and the back of the fetlock joint. A hit or trauma to the joint causes this ailment.
  • Shoe boil
    Shoe boil
    A shoe boil is the swelling of the elbow of a horse due to irritation caused by the hoof striking the elbow when lying down. Also called capped elbow. This affliction does not lead to lameness....

    , usually a blemish after the acute period
  • Sidebone
    Sidebone
    Sidebone is a common condition of horses, characterized by the ossification of the collateral cartilages of the coffin bone. These are found on either side of the foot protruding above the level of the coronary band. The lateral cartilages support the hoof wall and provide an important role in the...

  • Speedy cut - A speedy cut is from the striking of the inner lower side of the knee with the hoof of the opposite leg. The causes can be from poor conformation or an accident in the fields.
  • Splints
    Splints
    Splints is an ailment of the horse or pony, characterized by a hard, bony swelling, usually on the inside of a front leg, lying between the splint and cannon bone or on the splint bone itself. It may be "hot," meaning that it occurred recently and is still painful; or "cold," meaning that the...

     - Splints are a bony enlargement commonly on the inside of the front leg by the knee. The causes are poor conformation, rapid growth, trauma, or being struck by the other leg. Shin splints also known as bucked shins are the inflammation of the membrane that covers the cannon bone. They are caused by a hit to the area. They are usually a blemish after the acute period.
  • Sprain
    Sprain
    A sprain is an injury in a joint, caused by the ligament being stretched beyond its capacity. A muscular tear caused in the same manner is referred to as a strain. In cases where either ligament or muscle tissue is torn, immobilization and surgical repair may be necessary...

     - A sprain can be of the ankle or the suspensory ligament. An ankle sprain affects the ligaments that support the fetlock joint and a sprain of the suspensory causes inflammation and strain of the ligament.
  • Stocking up
    Stocking up
    Stocking up, also known as Filling up or Filled legs refers to a condition in horses caused when fluid builds up and swells the leg. Sometimes it is linked to lameness and other times it is purely an aesthetic problem. Fluid buildup can be caused by dozens of different things, though often is...

     - Stocking up is fluid retention in the lower back legs. The causes can be from poor circulation from lack in exercise, being confined to a stall that is too small, or the over feeding of grain. Stocking up can cause kidney problems in some cases.
  • Stringhalt
    Stringhalt
    Stringhalt is a sudden flexion of one or both hind legs in the horse, most easily seen while the horse is walking or trotting. It is most evident when the horse is backing up slowly, turning on the affected leg, or suddenly frightened. It involves one or both hind limbs of the horse...

  • Thoroughpin - Thoroughpin is the swelling of the deep digital flexor tendon sheath. Stress to the tendon from over work or over extension, trauma to the tendon and joint, or poor conformation of the hock joint can cause thoroughpin.
  • Windpuffs - Wind puffs also called wind galls is the spongy swelling around the back, front, or side of the fetlock joint. If the joint becomes inflamed the capsule swells up with more fluid. Hitting of the joint, excessive work when young, stress, and fatigue can cause wind puffs.

See also

  • Equine conformation
    Equine conformation
    Equine conformation evaluates the degree of correctness of a horse's bone structure, musculature, and its body proportions in relation to each other. Undesirable conformation can limit the ability to perform a specific task. Although there are several universal "faults," a horse's conformation is...

  • Skeletal system of the horse
    Skeletal system of the horse
    The skeletal system of the horse has three major functions in the body. It protects vital organs, provides framework, and supports soft parts of the body. Horses typically have 205 bones...

  • Equine anatomy
  • Horse hoof
    Horse hoof
    A horse hoof is a structure surrounding the distal phalanx of the 3rd digit of each of the four limbs of Equus species, which is covered by complex soft tissue and keratinised structures...

  • Horse care
    Horse care
    There are many aspects to horse care. Horses, ponies, mules, donkeys and other domesticated equids require attention from humans for optimal health and long life.-Living environment:...

  • Flexion test
    Flexion test
    A flexion test is a veterinary procedure performed on a horse, generally during a prepurchase or a lameness exam. The animal's leg is held in a flexed position for 30 seconds to up to 3 minutes , and then the horse is immediately trotted off and its gait is analyzed for abnormalities and uneveness...

  • Equine prepurchase exam
    Equine prepurchase exam
    When buying a horse, many buyers ask for an equine prepurchase exam. This serves to identify any preexisting problems which may hinder a horse’s future performance and reduce buyer risk...


External links

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