Lameness

Question 1

Majority of lameness occurs

Answer 1

Front legs

Knee down

Question 2

Most common site of lameness in front leg

Answer 2

foot

Question 3

Most common site of lameness in hind leg

Answer 3

Hock and stifle joints

Question 4

Supporting-leg lameness

Answer 4

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

Question 5

Examples of supporting-leg lameness

Answer 5

Laminitis and foot abscesses

Question 6

Swinging-leg lameness

Answer 6

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.

Question 7

Example of swinging-leg lameness

Answer 7

Pulled muscle

Question 8

Head bob w/ front leg lameness

Answer 8

Head will bob downward as the horse’s weight comes down on the sound leg

Question 9

Head bob w/ hind leg lameness

Answer 9

Head will bob downward as the horse’s weight comes down on the injured leg.

Question 10

Arthroscopy

Answer 10

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.

Question 11

Bone scans

Answer 11

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

Question 12

Magnetic resonance imaging

Answer 12

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.

Question 13

Nerve blocks

Answer 13

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

Question 14

Radiographs

Answer 14

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

Question 15

Synovial fluid analysis

Answer 15

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.

Question 16

Ultrasound

Answer 16

Ultrasound waves create pictures of soft tissues that cannot be seen on radiographs

Question 17

Unsoundness

Answer 17

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.

Question 18

Bone spavin

Answer 18

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

Question 19

Carpitis

Answer 19

Degenerative joint disease of the carpus. Usually caused by chronic repetitive trauma to the joint resulting in a
decreased ability to flex the joint.

Question 20

Osselets

Answer 20

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

Question 21

Pedal osteitis

Answer 21

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.

Question 22

Radial nerve paralysis

Answer 22

Trauma to the radial nerve will affect all the muscles along the humerus. Severe trauma almost
always leaves permanent damage

Question 23

Ringbone

Answer 23

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

Question 24

Sesamoiditis

Answer 24

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.

Question 25

Sidebone

Answer 25

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.

Question 26

Developmental Orthopedic Diseases (DOD)

Answer 26

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

Question 27

endochondral ossification

Answer 27

Converts cartilage to bone

Question 28

Three sites of endochondral ossification

Answer 28

1. Diaphysis, shaft of the bone
2. Physis, growth plate located at the junction of the shaft with the head of the bone
3. Epiphysis, the surface of the head of the bone that articulates with the joint

Question 29

Abnormal cartilage is prone to

Answer 29

fracture, fissure and breaking into small pieces which enter the joint.

Question 30

Angular limb deformities

Answer 30

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

Question 31

Most common angular limb deformities

Answer 31

Bow leg and knock-knees

Question 32

Arthritis

Answer 32

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.

Question 33

Three types of arthritis

Answer 33

1. Degenerative joint disease
2. Infectious or septic
3. Acute serious

Question 34

Degenerative joint disease

Answer 34

Arthritis resulting from an injury to the joint or to the ligaments supporting a joint. The
most common arthritic problem in adult horses

Question 35

Infectious or septic arthritis

Answer 35

Occurs when bacteria from the bloodstream enters the joint and destroys cartilage

Question 36

Acute serious arthritis

Answer 36

Characterized by swollen, tender, fluid-filled joints, along with lameness. The result of joint
stress or injury.

Question 37

Flexural limb deformities in foals

Answer 37

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

Question 38

Common sites for flexural limb deformities

Answer 38

1. fetlock joint
2. coffin joint
3. knee joint.

Question 39

Osteochondrosis and Osteochondritis Dissecans (OCD or OD)

Answer 39

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

Question 40

OCD/OD common sites

Answer 40

Stifles
Hocks
Shoulders
Fetlocks

Question 41

OCD/OD treatment

Answer 41

These can usually be removed through arthroscopic surgery

Question 42

Physeal dysplasia

Answer 42

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.