Laminitis Flashcards
what is another word for laminitis?
founder
does a horse stand on the ground?
no it is suspended by laminae inside a hoof capsule attached to P3
what happens with laminae is weakened by injury?
normal forces acting on digit cause shearing/tearing of laminae
how does the digit slip inside the hoof capsule downwards during laminitis?
weight of horse and rotation from pull of deep digital flexor
what are clinical signs of laminitis?
what is wrong?
widened white line - stretched laminae
Describe laminitis grade 1-4
what are the causes of laminitis?
endolrcrinopathic laminitis
enzymatic associated laminitis
support limb overload laminitis
black walnut toxicity
steroid induced laminitis
heat induced laminitis
what are the two examples of endocrinopathic laminitis?
equine metabolic syndrom/insulin dysfunction
pituitary pars intermedia dysfunction
what model is use to study endocrinopathic laminitis?
hyperinsulinemic model
what model is use to study enzymatic associated laminitis?
SIRS/endotoxemia
What is the pathophysiology of enzymatic model of laminitis?
-accumulates leukocytes in lamellar tissue
-metric metalloproteinases up regulated and cause basement membrane damage
what is the pathophysiology of endocrinopathic laminitis?
lamellar epithelial cell stretching
not induced by inflammation
what is the pathophysiology of support limb laminitis?
loading cycle (offloading and loading the feet) through walking, or shifting weight when standing still, helps to maintain BF to lamellar tissue
stop moving so BF reduced
what does the clinical damage in laminitis?
forces acting on digit (weight of horse)
How is laminitis diagnosed?
radiographs - stand horse evenly on blocks and take both later and dorsal palmar (DP) views
what are the abnormal signs seen in an acute laminitis radiograph?
jet line - edema of laminae
possibly no overt changes
what are the abnormal signs seen in an chronic laminitis radiograph?
ski tipping of P3
loss of parallel between dorsal hoof wall and dorsal P3
medial to lateral asymmetry
sinking
what is the normal found distance?
2-15mm
sinking determined by extensor process to coronet length
what should the cobb angle be? what does it determine?
0 - determines rotation
hoof wall and dorsal P3 should be parallel
what should palmer angle be?
3-10 degrees but bony alignment is key
what is the normal sole depth?
15-20mm
what is the dorsal hoof wall thickness?
<18-20mm
what is the black line?
bony alignment
Label
Label
what areas are evaluated in a venogram of a hoof?
terminal arch
coronary papillae (makes up coronary plexus)
sublamellar vascular bed
circumflex vessels
lamellar-circumflex junction with terminal papillae
what are venograms useful for?
determine progress of deterioration
what is wrong?
falling caudally, backward ledge
what does a return to normal venogram for laminitis within first 4 weeks indicates?
an excellent chance for return to use
What drugs would you use for acute laminitis?
phenylbutazone - NSAID to dec inflammatory cytokines and pain
DMSO - reduce edema and reduce ischemia reperfusion injury
Pentoxyphylline - alter RBC membrane to make more deformable and improve BF
Acepromazine - tranquilizer, inc digital BF
Opioids - butorphanol, fentanyl patches
Anticoagulant thearpy - reduce micro thrombi that can compromise vasculature in foot
what has been shown to be slightly protective during colic/colitis?
anticoagulant thearpy
what is the goal of acute laminitis?
decrease pull of DDF
How can you decrease tension on DDF?
farrier care - elevate heels with wedge or Redden shoe, trim shoes
DDT tenotomy - for rotating not sinking, salvage
How long do you do cryotherapy for acute laminitis?
48 hours continuous cryotherapy to distal limbs
5L bag with hoof, ice, and water taped into place
when is sole/frog support used in acute laminitis?
thin soles/sinking
How can the tension of the suspensory apparatus of distal phalanx be reduced?
strict stall rest
encourage to lie down with very deep bedding or sand
what is the prognosis for acute alminitis?
wait and see - depends on each horse and how they respond to therapy
if lots of $$$ use venogram to get idea
How is chronic laminitis treated?
farrier care and control of underlying disease absolutely critical
what are most chronic laminitis?
endocrinopathic laminitis - must manage primary disease
what is the farrier concept for laminitis?
realign the bony column - remove toe and heel aggressively
How is PPID caused laminitis treated?
prascend
How is insulin dysregulation laminitis treated?
metformin, levothyroxine
How is chronic laminitis nutritionally managed?
low starch < 10% NSC
How is chronic laminitis footing treated?
deep, soft, supportive
How is chronic laminitis pharmacologically treated?
NSAIDS
Phenylbutazone
firocoxib
what does the prognosis for chronic laminitis depend on?
farrier, veterinarian working together
stoicism of horse
how primary disease responds to treatment
