LA Ortho - Laminitis

Question 1

What is laminitis

Answer 1

Multi factorial disease process
Disturbance of connective tissue bond between inner hoof wall and coffin bone (lamellar apparatus)

Question 2

Distribution of laminitis

Answer 2

Common cause for bilateral forelimb lameness

Question 3

Where does separation in laminitis occur

Answer 3

Between the epidermal lamellae and dermal lamallae

Question 4

Consequences of lamellae separation

Answer 4

Can compromise blood flow
Microthrombi
Vasoconstriction

Question 5

Why is failure at lamellar face detrimental

Answer 5

Hoof wall is major weight bearing aspect of hoof, separation, swelling in this loading aspect is extremely painful

Question 6

Clinical signs of laminitis

Answer 6

Very marked severe lameness - often recumbent
Elevated, bounding digital pulses, heat in hoof capsule
Front feet are most commonly effected, all 4 can be

Question 7

Causes for laminitis

Answer 7

Septic or inflammatory conditions
Endocrine or metabolic abnormalities
Excessive unilateral weight bearing

Question 8

Septic or inflammatory condition - secondary to laminitis

Answer 8

Endotoxemia
Carbohydrate overload (pasture, grain)
GI disturbances (enteritis, strangulated bowel)
septic conditions (retained placenta)

Question 9

Endocrine or metabolic abnormalities

Answer 9

Most common in field
Pituitary pars intermedia dysfunction (PPID) cushings
Insulin dysregulation
Obesity

Question 10

Excessive unilateral weight bearing

Answer 10

Secondary to a fracture or single leg injury can lead to laminitis developing in a single leg usually the contra lateral limb

Question 11

Grain overload induced laminitis

Answer 11

Excess non structural carbohydrate enters LI
Lactic acid bacteria “feeding frenzy”
Intraluminal pH drops and damages intestinal mucosal barrier
Trigger factors enter systemic circulation (systemic inflammation) and can travel to foot = laminar inflammation

Question 12

Possible sequelae

Answer 12

No lameness or distal phalanx-hoof wall separation (insult was mild)
Lameness without distal phalanx-hoof wall separation (moderate insult)

Question 13

Severe insult and very severe insult

Answer 13

Lameness and distal rotation of the distal phalanx - severe, critical threshold of supporting laminate was lost
Lameness & vertical displacement of distal phalanx - very sever, “sinking” p3 can penetrate sole. Total derangement of lamellar apparatus

Question 14

Management of laminitis

Answer 14

Best outcome is if treatment occurs prior to clinical signs
- preventative measures
Clinical signs present = emergency situation
Intensive cases - referral

Question 15

Management of laminitis

Answer 15

Remove inciting cause /correct
Control pain /inflammation
Reduce derangement of laminar blood flow
Minimize mechanical trauma to weakened lamellae

Question 16

Remove/correct problem

Answer 16

Depends on situation
- overweight horse
- cushings horse
- feed room break in
- damaged /fractured limb

Question 17

Control pain & inflammation

Answer 17

NSAIDS- block prostaglandins
Polymixin B - good for Endotoxemia
Pentoxifylline

Question 18

Cryotherapy

Answer 18

Decreased blood flow and metabolic rate of damage
Maintain hoof wall temperature for 48-72 h or longer

Question 19

Reduce derangement of blood flow to laminar tissue

Answer 19

Ace - vasodilator
Isoxsuprine -
Pentoxifylline - decrease blood viscosity

Question 20

Minimizing mechanical trauma

Answer 20

Relieve weight supporting demand on injury leg
Recruit other structures to load share (sole, frog) takes weight away from lamellar tissue

Question 21

Radiographic monitoring

Answer 21

Radio ASAP w presentation of clinical signs
Views: LM, DP
Repeat every 2-5 days until horse is stabilizes
Can utilize venograms to monitor blood flow