LA Ortho - Laminitis Flashcards
What is laminitis
Multi factorial disease process
Disturbance of connective tissue bond between inner hoof wall and coffin bone (lamellar apparatus)
Distribution of laminitis
Common cause for bilateral forelimb lameness
Where does separation in laminitis occur
Between the epidermal lamellae and dermal lamallae
Consequences of lamellae separation
Can compromise blood flow
Microthrombi
Vasoconstriction
Why is failure at lamellar face detrimental
Hoof wall is major weight bearing aspect of hoof, separation, swelling in this loading aspect is extremely painful
Clinical signs of laminitis
Very marked severe lameness - often recumbent
Elevated, bounding digital pulses, heat in hoof capsule
Front feet are most commonly effected, all 4 can be
Causes for laminitis
Septic or inflammatory conditions
Endocrine or metabolic abnormalities
Excessive unilateral weight bearing
Septic or inflammatory condition - secondary to laminitis
Endotoxemia
Carbohydrate overload (pasture, grain)
GI disturbances (enteritis, strangulated bowel)
septic conditions (retained placenta)
Endocrine or metabolic abnormalities
Most common in field
Pituitary pars intermedia dysfunction (PPID) cushings
Insulin dysregulation
Obesity
Excessive unilateral weight bearing
Secondary to a fracture or single leg injury can lead to laminitis developing in a single leg usually the contra lateral limb
Grain overload induced laminitis
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
Possible sequelae
No lameness or distal phalanx-hoof wall separation (insult was mild)
Lameness without distal phalanx-hoof wall separation (moderate insult)
Severe insult and very severe insult
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
Management of laminitis
Best outcome is if treatment occurs prior to clinical signs
- preventative measures
Clinical signs present = emergency situation
Intensive cases - referral
Management of laminitis
Remove inciting cause /correct
Control pain /inflammation
Reduce derangement of laminar blood flow
Minimize mechanical trauma to weakened lamellae
Remove/correct problem
Depends on situation
- overweight horse
- cushings horse
- feed room break in
- damaged /fractured limb
Control pain & inflammation
NSAIDS- block prostaglandins
Polymixin B - good for Endotoxemia
Pentoxifylline
Cryotherapy
Decreased blood flow and metabolic rate of damage
Maintain hoof wall temperature for 48-72 h or longer
Reduce derangement of blood flow to laminar tissue
Ace - vasodilator
Isoxsuprine -
Pentoxifylline - decrease blood viscosity
Minimizing mechanical trauma
Relieve weight supporting demand on injury leg
Recruit other structures to load share (sole, frog) takes weight away from lamellar tissue
Radiographic monitoring
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
