Lameness

Question 1

Define lameness

Answer 1

having a body part and especially a limb so disabled as to impair freedom of movement; an abnormality in gait or way of moving

Question 2

List the 3 pathophysiological causes of lameness

Answer 2

pain
mechanical impairment of a limb or joint
neurologic dysfunction to limbs

Question 3

What abnormalities can cause pain in lameness. Give examples

Answer 3

o Abnormalities affecting the soft tissue of the limb (tendonitis, bursitis), muscle inflammation (rhabdomyolysis), joint inflammation/infection (arthritis, septic arthritis)
o Abnormalities of the bone such as fractures and inflammation

Question 4

Give examples of mechanical impairment of a limb or joint

Answer 4

Result of fibrosis of soft tissue (muscle contracture) or within a joint (ankylosis)

Question 5

What Dz is common for causing lameness due to neurological reasons

Answer 5

Equine Protozoal Myeloencephalitis (EPM)

Question 6

2 Goals of lameness evaluation

Answer 6

1. Identify the location of lameness

2. Identify the source of lameness in that location

Question 7

What are some questions you should ask when you get a history for a lame patient?

Answer 7

• Duration of problem
• When problem first noticed
• Is there any progression
• Does it change with exercise
• Any other abnormalities
• Is there a specific location
• Is there a known cause/source
• How long the client has had the horse
• Any previous injuries/illnesses
• Investigate any therapeutic strategies used
• Investigate hoof care

Question 8

What things are evaluated on a PE for lameness?

Answer 8

• Evaluate from afar: overall stance, BCS, general health
• Thorough manipulation and palpation of all 4 limbs, neck, and pelvis area looking for pain, swelling, heat, redness, or other physical abnormalities
• Observation while horse is in motion to see if lameness is exacerbated
  - walk in straight line or tight circles
  - under tack in performance conditions
  - change ground surface to cement or asphalt

Question 9

List 3 additional tests for lameness

Answer 9

1. flexion test
2. nerve blocks
3. digital imaging

Question 10

What is a flexion test? Why is it done?

Answer 10

placing a joint in flexion and holding it for a period of time to exacerbate any pain or inflammation in or around that joint in an effort to highlight lameness associated with the joint

Question 11

What is the theory behind nerve blocks? How do you give nerve blocks to evaluate lameness?

Answer 11

the theory is if a horse is lame due to a painful condition, when the affected area is anesthetized the horse will walk normally again

regional anesthesia is given starting at the digit and working proximally if the horse is still lame after the first region has been anesthetized

Question 12

What 3 types of digital imaging can be used and for what purpose(s)?

Answer 12

• Rads –> presence of fractures, abnormal bone, soft tissue swelling or joint abnormalities (effusion, osteochondrosis dissecans lesions)
• Ultrasound–> presence of edema or other fluid suggesting inflammation
• Nuclear Scintigraphy (Bone Scan) –> identify location of an abnormality that is particularly difficult to find