Diagnosing Lameness in the Horse

Question 1

What is the definition of lameness?

Answer 1

Alteratiion of the normal gait pattern caused by a functional or structural disorder in the locomotor system.

Question 2

What is lameness usually due to?

Answer 2

PAIN!

Question 3

What can be 3 general forms of lameness?

Answer 3

Neurologic
Metabolic
Mechanical

Question 4

When performing a pre-purchase exam, who do you work for?

Answer 4

Buyer

Question 5

What are the 7 classic steps of a lameness exam?

Answer 5

History
PE
Palpation
Observation at exercise
Flexion tests
Diagnostic nerve blocks
Diagnostic imaging

Question 6

What is the primary goal of a lameness exam?

Answer 6

Localization and diagnosis.

Question 7

When trying to determine duration of the lameness, what is a better question to ask the owner?

Answer 7

When was the horse last normal?

Question 8

What are you looking for on the distance portion of a lameness exam?

Answer 8

Symmetry

Question 9

What are you looking for on the close-up portion of a lameness exam?

Answer 9

Symmetry

Question 10

What is a good thing to do to help establish normals?

Answer 10

Looks at the contralateral limb.

Question 11

What should you do with EVERY lameness you see?

Answer 11

Put hoof testers on it.

Question 12

What are 2 things you are assessing when observing stride?

Answer 12

Length of stride

Foot placement

Question 13

What are 6 things to watch for when observing at exercise?

Answer 13

Stride
Foot flight arc
Path of the foot flight
Foot strike
Joint angles
Gluteal excursion

Question 14

What gait is lameness graded at?

Answer 14

At a trot

Question 15

What is the best surface for a lameness exam?

Answer 15

Firm and even

NOTE: You may need different surfaces, hills etc.

Question 16

“Down on the sound” means..?

Answer 16

The head will bob down when the horse is landing on the normal/sound front limb. Conversely it will come up on the lam front limb.

Question 17

What are you watching for mostly when assessing the hind end of lameness?

Answer 17

A “hip hike” or increased gluteal excursion.

Question 18

What structure should you never put your hoof testers on?

Answer 18

The coronary band.

Question 19

What is a Grade 1 lameness on the AAEP Lameness scale?

Answer 19

Difficult to observe, inconsistent

Question 20

What is a Grade 2 lameness on the AAEP Lameness scale?

Answer 20

Difficult to see in a straight line, but consistently seen under certain circumstances.

Question 21

What is a Grade 3 lameness on the AAEP Lameness scale?

Answer 21

Consistently seen at a trot under all circumstances.

Question 22

What is a Grade 4 lameness on the AAEP Lameness scale?

Answer 22

Obvious with marked head nod, hitching and shortened stride.

Question 23

What is a Grade 5 lameness on the AAEP Lameness scale?

Answer 23

Minimal/non-weight bearing. Can’t move.

Question 24

What are 5 pathognomonic lameness’ diagnose at the walk?

Answer 24

Peronius tertius rupture
Upward fixation of the patella
Stringhalt
Fibrotic myopathy
Sweeny

Question 25

What will you see in a peroneus tertius rupture?

Answer 25

Can extend the hock while the stifle is flexed, and you may see an "S" curve below the SMST (this is the ruptured muscle, ouchie!)

Question 26

What is stringhalt?

Answer 26

Hyperflexion of the hind limb.

Question 27

What is fibrotic myopathy?

Answer 27

Fibrosus of the SMST

Question 28

What is Sweeny?

Answer 28

Nerve damage resulting in the atrophy of the supra-and infraspinatus muscles.

Question 29

When do you perform your flexion tests?

Answer 29

AFTER palpation, observation at exercise and using hoof testers.

Question 30

What is a positive flexion test?

Answer 30

Exacerbated lameness.

Question 31

How do you perform a flexion test?

Answer 31

Flex the joint of interest and trot off in a straight line immediately after.

Question 32

When performing a flexion test on a distal forelimb, which joint are you flexing and for how long?

Answer 32

Just trying to flex at the carpus for 30 seconds.

Question 33

When performing a flexion test on the proximal forelimb, which joint are you flexing and for how long?

Answer 33

Carpal joint for 60 seconds. NOTE: You end up flexing the carpus, elbow and shoulder.

Question 34

When performing a flexion test on a distal hindlimb, which joint are you flexing and for how long?

Answer 34

Just trying to flex at the carpus for 30 seconds.

Question 35

When performing a flexion test on the proximal hindlimb, which joint are you flexing and for how long?

Answer 35

The hock, stifle and hip for 90 seconds. NOTE: This test is NOT hock specific.

Question 36

Why do you perform nerve blocks?

Answer 36

To localize the lameness.

Question 37

When performing nerve blocks, where do you begin?

Answer 37

Distally and work proximally.

Question 38

When performing nerve blocks, why do you not want to use sedation?

Answer 38

Sedation makes it more challenging to watch them go. NOTE: If they're being jerks, you can use a little Ace.

Question 39

What 4 different methods can you use when performing nerve blocks?

Answer 39

Perineural (nerve block) Regional Direct infiltration (ie. if you have a big mass) Intraarticular

Question 40

What is a reason NOT to perform a nerve block?

Answer 40

Severe lameness.

Question 41

What agents might you use in a nerve block?

Answer 41

Lidocaine Mepivacaine Bupivacaine

Question 42

What kind of volume should you use with perineural anesthesia?

Answer 42

The smallest volume possible

Question 43

When doing a skin test (to test your nerve block), what do you use first?

Answer 43

A blunt instrument.

Question 44

From distal to proximal, what 6 nerve blocks can you perform?

Answer 44

``` Palmar digital Basi-sesamoid Abaxial sesamoid Low and high 4 point MUN (forelimb) Peroneal/tibial (hindlimb) ```

Question 45

What at the landmarks for the palmar digital nerve block?

Answer 45

Groove between the flexors and the ergot medially and laterally.

Question 46

What does the palmar digital nerve block anesthetize?

Answer 46

Essentially the whole foot.

Question 47

What are 3 main reasons why the palmar digital nerve block might fail?

Answer 47

Adhesions between the navicular bone and the DDFT Osteoarthritis Improper/incomplete anesthesia

Question 48

What 6 structures does the abaxial (basisesamoid) nerve block anesthetize?

Answer 48

``` Foot, P2 Distopalmar P1 Proxiaml and distal interphalangeal joints Distal SDFT and DDFT Distal sesamoidean ligament Distal annular ligament ```

Question 49

What nerves does the low 4-point block?

Answer 49

Lateral and medial palmar metacarpal nerve | Lateral and medial palmar nerve

Question 50

What volume should you use in the low 4-point block?

Answer 50

3mL per palmar nerve and 1mL per palmar metacarpal nerve

Question 51

What structures does the low 4-point block?

Answer 51

Everything from the fetlock down.

Question 52

What risk is there when using a high 4-point?

Answer 52

Could enter synovial structures.

Question 53

What block can you used instead of a high 4-point?

Answer 53

Lateral palmar nerve block

Question 54

What structures are anesthetized with a high 4-point block?

Answer 54

Suspensory ligament Some flexor tendons Some of metacarpal III and metacarpal IV

Question 55

What does the lateral palmar nerve block block?

Answer 55

The origin of the suspensory ligament.

Question 56

If you're doing joint blocks, can you start high and go low?

Answer 56

Yes, because it should be intraarticular.