Equine Lameness Flashcards
Steps in Lameness Exam (6)
- History
- Observe at Rest
- Observe in Motion
- Palpation - Hoof Testing
- Grade Lameness
- Diagnostic Testing
Gait Faults
Abnormal leg actions that occur while the horse is in motion
Front Leg Lameness
“Down on Sound”
* Head down on good leg
* Head up on bad front leg
* Shorter stride with affected limb
Hind Leg Lamness
Croup rises on affected side
Palpation
Flexion Test
Steps in Lameness Exam
- Start on lower part of leg and work up
- Flex joints (small <1 min, large 1-2 min)
- Immediately jog horse and look for lameness
- Normal to have 3-4 off strides initially
Palpation
Hoof
Steps in Lameness Exam
Majority of lameness originates in hoof
* check confirmation
* test for pain
* check digital pulses
* check bottom of hoof
Lameness Grade
Steps in Lameness Exam
- 0 = normal
- 1 = difficult to see / not consistent
- 2 = consistently apparent, but difficult to at walk or trot
- 3 = consistently apparant at trot
- 4 = apparant at walk
- 5 = minimal or non-weight bearing / unable to move
Diagnostics
Nerve Blocks
Steps in Lameness Exam
- Injection given around nerve / into joint or tendon shealth
- Object pushed against area; reaction noted
- If none, horse is trotted to look for lameness
- Improvement = cause was structure able to be blocked
- Start low and work upwards
Nerve Block
Drugs
- Lidocaine
- Mepivacaine
- Bupivicaine
Diagnostics
X-Rays vs Ultrasounds
Steps in Lameness Exam
X-Rays
* better for bone
Ultrasound
* better for soft tissue
Diagnostics
MRI
Magnetic Resonance Imaging
* gold standard for soft tissue injury in foot
* image restricted to stifle/elbow or below
* not advised if lameness not localized
* limited availability / high cost
Diagnostic
CT
Steps in Lameness Exam
Computed Tomography
* x-rays taken in a series
* converted to 3D images
* anesthesia used
* costly / less available
* less time and cost than MRI
Diagnostic
Nuclear Scintigraphy
- For multifocal lameness
- IV injection of Technetium-99 (radioactive isotope)
- Goes into areas of bone remodeling
- Gamma camera detects rays emmited
Diagnostics
Thermography
Steps in Lameness Exam
Infared camera that measures heat gradients
* inflammation = heat
* non-invasive
* non-contact
Common Causes of Lameness in Feet
- Hoof abscess or solar bruising
- Navicular syndrome
- Laminitis
- Fracture of third phalanx (P3 / coffin bone)
Navicular Disease
Degenerate change in the navicular bone
* number 1 chronic intermittent front limb lameness
* those with short heel, long toe / upright pastern are predisposed
* Limited treatment - increase blood flow and improve bone density
Laminitis
Horse has a leaning back stance
* “walking on eggshells”
* see mostly in adults
* common for both front or all 4 feet
* Many causes - sepsis / endotoxemia, trauma, Cushings
Acute Laminitis
- Sub Acute - mild, no rotation; signs resolve quickly
- Acute - ER first 72 hrs of signs; treat within 12 hrs
- Refractory - minimal / no response within 7 - 10 days
Chronic Laminitis
- Early Chronic - rotation of coffin bone; takes days-months to heal
- Chronic Active - rotation of coffin bone; unstable and could penetrate sole
- Chronic Stable
Hoof Testing
Diffuse Sensitivity
All over; non-localized
* Fracture
* Infection of coffin bone
* Laminitis
Hoof Testing
Localized Sensitivity
- Sole bruising
- Puncture wounds
- Hoof abcesses
- Hot nails (recent shoeing)
Hoof Testing
Frog Sensitivity
Sensitivity over middle third of frog
* navicular syndrome
* sheared heels
Hoof Testing
Hoof Wall
Use of a hammer to hit hoof and look for response
* cracks in hoof
* gravel - hoof abscess travels up hoof wall towards coronary band
Horse Foot
- A - Coffin Bone
- B - Navicular Bone
- C - Short Pastern Bone
- D - Long Pastern Bone
Stringhalt
Involuntary flexion of the hock during forward movement
* affects one or both hindlimbs
* unknown cause - possible nerve degeneration
* movement often exaggerated
* surgical treatment to remove part of the tendon
* untreated horses will worsen with age
