Lameness Flashcards
Majority of lameness occurs
Front legs
Knee down
Most common site of lameness in front leg
foot
Most common site of lameness in hind leg
Hock and stifle joints
Supporting-leg lameness
Made worse when the horse shifts its weight onto the sore limb.
The horse will attempt to rest the affected limb by removing weight from that leg
Examples of supporting-leg lameness
Laminitis and foot abscesses
Swinging-leg lameness
Made worse when the horse “swings” or moves the limb.
The horse will try to protect the affected area by shortening the reach of the leg as it moves.
Example of swinging-leg lameness
Pulled muscle
Head bob w/ front leg lameness
Head will bob downward as the horse’s weight comes down on the sound leg
Head bob w/ hind leg lameness
Head will bob downward as the horse’s weight comes down on the injured leg.
Arthroscopy
A fiber optic scope is passed through the skin via a small incision, allowing for direct visual inspection of the
interior of a joint. Surgery to repair a joint can be done at the same time. This is primarily performed at equine medical centers.
Bone scans
Also known as nuclear scintigraphy, this method of imaging uses intravenous radioactive isotopes and scintigraphy equipment to create pictures of the bones and surrounding tissues. These are primarily performed at equine medical centers
Magnetic resonance imaging
MRI scanners use strong magnetic fields and radio waves to generate images of the structures in the limb. These are primarily performed at equine medical centers.
Nerve blocks
Local anesthetics are injected around specific nerves to localize pain and lameness. Nerve blocks do not
deliver a diagnosis, but assist in localizing the source of the pain
Radiographs
Also known as X-rays, these images show the bones of the area in detail and allow a veterinarian to look
for fractures or other bone issues
Synovial fluid analysis
Normal synovial fluid is clear and pale yellow. The presence of blood in synovial fluid indicates
that bleeding has occurred into the synovial space due to an injury. Often, laboratory analysis of the fluid helps in providing further information.
Ultrasound
Ultrasound waves create pictures of soft tissues that cannot be seen on radiographs
Unsoundness
A horse is considered unsound when, by virtue of an old injury or conformation defect, it is unable to perform at the level for which it was intended.
Bone spavin
Osteoarthritis of the tarsal bones involving the lower hock joint. Can be caused by cartilage compression,
uneven loading, conformation, or any activity which requires a lot of joint flexion
Carpitis
Degenerative joint disease of the carpus. Usually caused by chronic repetitive trauma to the joint resulting in a
decreased ability to flex the joint.
Osselets
Traumatic arthritis of the metacarpophalangeal joint. Visible swelling on the front of the fetlock joint usually
points to arthritis developing on the lower end of the third metacarpal bone and the high end of the first phalanx bone
Pedal osteitis
Inflammatory reaction localized along the solar margin of the third phalanx bone. Usually associated with
horses working on hard surfaces who are subject to constant concussive trauma.
Radial nerve paralysis
Trauma to the radial nerve will affect all the muscles along the humerus. Severe trauma almost
always leaves permanent damage
Ringbone
Also known as phalangeal exotosis.
New bone growth that originates and forms on the dorsal, dorsolateral, or dorsomedial surfaces of the first and second phalanx bones, and the extensor process of the third phalanx bone.
The most
common cause is trauma causing strain on the collateral ligaments, strain on the joint capsule, or a direct blow to the area. Conformational defects can also lead to ringbone
Sesamoiditis
Periostitis of the digital sesamoid bones following sprains of the distal sesamoid ligaments.
Periostitis and new bone formation occur where the suspensory ligament attaches to the sesamoid bones.
Sidebone
Ossification of the collateral cartilages of the third phalanx bone.
Common in the front feet of horses working on hard surfaces or when subjected to long term unbalanced shoeing.
Developmental Orthopedic Diseases (DOD)
Any mistakes in how the cartilage converts to bone can either delay
the ossification process or leave damaged cartilage which fails to mature into healthy bone
endochondral ossification
Converts cartilage to bone
Three sites of endochondral ossification
- Diaphysis, shaft of the bone
- Physis, growth plate located at the junction of the shaft with the head of the bone
- Epiphysis, the surface of the head of the bone that articulates with the joint
Abnormal cartilage is prone to
fracture, fissure and breaking into small pieces which enter the joint.
Angular limb deformities
Congenital limb deformities are caused by abnormal limb placement in the uterus, nutritional
imbalances in the mare, neonatal hypothyroidism and unequal growth between the two sides of a long bone
Most common angular limb deformities
Bow leg and knock-knees
Arthritis
This describes a number of joint ailments including inflammation, degeneration, and new bone formation in and around joints.
Most arthritis causes stiffness and diminished range of motion of the joint.
Three types of arthritis
- Degenerative joint disease
- Infectious or septic
- Acute serious
Degenerative joint disease
Arthritis resulting from an injury to the joint or to the ligaments supporting a joint. The
most common arthritic problem in adult horses
Infectious or septic arthritis
Occurs when bacteria from the bloodstream enters the joint and destroys cartilage
Acute serious arthritis
Characterized by swollen, tender, fluid-filled joints, along with lameness. The result of joint
stress or injury.
Flexural limb deformities in foals
Also known as contracted digital flexor tendons.
Either the deep or superficial (or both) digital flexor tendons in the forelegs are contracted, producing a raised heel and a club foot.
In mild cases, the foal appears to walk on its toes. In severe cases, the foal bears weight on the front of the fetlock
Common sites for flexural limb deformities
- fetlock joint
- coffin joint
- knee joint.
Osteochondrosis and Osteochondritis Dissecans (OCD or OD)
Extremely common in growing horses
Results from a primary defect in the process by which cartilage is converted to bone. Thickened cartilage within the joint fragments and breaks into loose pieces of cartilage
OCD/OD common sites
Stifles
Hocks
Shoulders
Fetlocks
OCD/OD treatment
These can usually be removed through arthroscopic surgery
Physeal dysplasia
A generalized bone disease that causes lameness in young horses due to the enlargement of the growth
plates located at the juncture of the shaft with the head of the bone causing a flaring at the end of the bone.
This occurs in rapidly growing foals up to two years of age. Previously known as epiphysitis.
