1. Lameness Investigation

Question 1

What is lameness

Answer 1

Clinical sign that results in gait abnormality
characterised by limping

Question 2

Equine gait cycle

Answer 2

Weight bearing phase — stance

Question 3

Weight bearing phase of gait

Answer 3

Hyperextension of the fetlock

Question 4

What are cranial and caudal phases of the stride?

Answer 4

Cranial — in front of the vertical
Caudal — behind the vertical

Question 5

In what positions and in what gaits should we check lameness?

Answer 5

Walk and trot
From the sides and from front/behind

Question 6

Recognition of the lameness in front limb

Answer 6

• elevation of the head and neck during putting lame limb (head nod)
• extension of the fetlock
• irregular rhythm (look and listen)
• phases of the stride
• foot flight (arc)

Question 7

Recognition of lameness in hindlimb

Answer 7

• asymmetrical movement of the hindquarters (lame side dropping more; pelvic hike of tuber sacrale (this movement is more subtle)
• no tracking up straight
• foot flight (arc) (stumbling, toe drag)
• fetlock extension
• irregular rhythm (look and listen)

Question 8

AAEP grading system
(American association of equine practitioners)

Answer 8

0:Lameness not perceptible under any circumstances

1:Lameness is difficult to observe and is not consistently apparent, regardless
of circumstances (e.g. under saddle, circling, inclines, hard surface, etc.)

2:Lameness is difficult to observe at a walk or when trotting in a straight line
but consistently apparent under certain circumstances (e.g. weight-
carrying, circling, inclines, hard surface, etc.)

3:Lameness is consistently observable at a trot under all circumstances

4:Lameness is obvious at a walk

5:Lameness produces minimal weight bearing in motion and/or at rest or a complete inability to move.

Question 9

How to describe lameness

Answer 9

• lameness grading
• consistency (consistent <-> intermittent)
• under which circumstances its the most severe
• other details
• description of the canter

Question 10

Supporting vs swinging limb lameness

Answer 10

Depending on the phase of the stride when the disturbance is caused.
Supporting limb lameness is caused by pain during the stance phase,
Swinging limb lameness is caused by problems during the swing phase

BUT very often mixed, may very under different circumstances, not very reliable differentiation

Question 11

Forelimb or hindlimb lameness?

Answer 11

Moderate to severe hindlimb lameness often
mimics ipsilateral (on the same side) forelimb lameness

Which is primary?
• Provocation tests
• Lunge
• Ridden exercise
• Diagnostic anaesthesia

Question 12

Steps of lameness investigation

Answer 12

• History
• Observation
• Palpation
• Provocation tests
• Diagnostic anaesthesia (Perineural, intrasynovial, infiltration)
• Diagnostic imaging (Radiography, Ultrasound, CT, MRI, Scintigraphy)

Question 13

History taken in case of lameness

Answer 13

• Age, breed, discipline
• When did the lameness start?
• Sudden / insidious onset
• Trauma?
• Severity and consistency
• Work history
• Previous lameness
• Any treatment, medication + response
• When was the horse last shod/trimmed

Question 14

What is going on here? Can we immediately diagnose?

Answer 14

Rupture of ….

Question 15

Examination in the stable

Answer 15

• posture
• obvious swelling
• palpate all four limbs, neck, back, pelvis
• heat, swelling, tension, discomfort
• range of movement of joints and spine
• hoof testers

Question 16

Gait evaluation in case of lameness

Answer 16

In hand
• Even surface
• Walk and trot – from the side and behind/in front
• Include small circles in walk
• Flexion test

On the lunge

If possible, ridden

Question 17

Flexion test of the forelimb

Answer 17

• distal limb
• carpus
• specific manipulation of the proximal limb if needed

Question 18

Flexion test of the hindlimb

Answer 18

• proximal limb
• distal limb
• specific manipulation of the proximal limb if needed

Question 19

Flexion test. How to do it?

Answer 19

• Hold the limb for one minute
• Try to avoid applying focal pressure
• After let the horse trot
• Always do both limbs
• Same person should do both limbs
• Good idea to start with the non-lame limb (to understand what is normal)

If lameness appear more noticeable after flexion test -> positive

Question 20

What are the next steps after lame limb is identified?

Answer 20

• diagnostic anaesthesia to localise the source of pain
• diagnostic imaging

Question 21

Causes of lameness

Answer 21

1. Trauma
2. Degenerative, repetitive wear and tear (osteoarthritis, tendon lesions)
3. Congenital
4. Developmental (osteochondrosis dissecans)
5. Infection
6. Mechanical (e.g. upward fixation of the patella)
7. Neurological (not always easy to differentiate)

Question 22

Example of congenital lameness

Answer 22

Split novicular bone

Question 23

Stringhalt — ?

Answer 23

Stringhalt — sudden flexion of one or both hind legs in the horse. Spasmodic contraction of the lateral extensor tendons of the hind limb.

Flat weed is suspected cause.
Long digital extensor muscle appears to be the most affected.