1. Lameness Investigation Flashcards
What is lameness
Clinical sign that results in gait abnormality
characterised by limping
Equine gait cycle
Weight bearing phase — stance
Weight bearing phase of gait
Hyperextension of the fetlock
What are cranial and caudal phases of the stride?
Cranial — in front of the vertical
Caudal — behind the vertical
In what positions and in what gaits should we check lameness?
Walk and trot
From the sides and from front/behind
Recognition of the lameness in front limb
- 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)
Recognition of lameness in hindlimb
- 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)
AAEP grading system
(American association of equine practitioners)
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.
How to describe lameness
- lameness grading
- consistency (consistent <-> intermittent)
- under which circumstances its the most severe
- other details
- description of the canter
Supporting vs swinging limb lameness
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
Forelimb or hindlimb lameness?
Moderate to severe hindlimb lameness often
mimics ipsilateral (on the same side) forelimb lameness
Which is primary?
• Provocation tests
• Lunge
• Ridden exercise
• Diagnostic anaesthesia
Steps of lameness investigation
• History
• Observation
• Palpation
• Provocation tests
• Diagnostic anaesthesia (Perineural, intrasynovial, infiltration)
• Diagnostic imaging (Radiography, Ultrasound, CT, MRI, Scintigraphy)
History taken in case of lameness
• 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
What is going on here? Can we immediately diagnose?
Rupture of ….
Examination in the stable
- posture
- obvious swelling
- palpate all four limbs, neck, back, pelvis
- heat, swelling, tension, discomfort
- range of movement of joints and spine
- hoof testers
Gait evaluation in case of lameness
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
Flexion test of the forelimb
- distal limb
- carpus
- specific manipulation of the proximal limb if needed
Flexion test of the hindlimb
- proximal limb
- distal limb
- specific manipulation of the proximal limb if needed
Flexion test. How to do it?
• 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
What are the next steps after lame limb is identified?
- diagnostic anaesthesia to localise the source of pain
- diagnostic imaging
Causes of lameness
- Trauma
- Degenerative, repetitive wear and tear (osteoarthritis, tendon lesions)
- Congenital
- Developmental (osteochondrosis dissecans)
- Infection
- Mechanical (e.g. upward fixation of the patella)
- Neurological (not always easy to differentiate)
Example of congenital lameness
Split novicular bone
Stringhalt — ?
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.
