Foundational Laminitis Flashcards
what is the stratum externum?
thin, outermost layer
cell of stratum spinosum differentiate into cells of _____________________
stratum corneum
what does the dermis of the hoof provide?
blood supply and nutrients to epidermis
what is the blood supply of the hoof?
palmar digital arteries and veins
what innervates the hoof?
palmar digital nerve
what is the most common type of laminitis?
endocrinopathic laminitis
what conditions are associated with endocrinopathic laminitis?
equine metabolic syndrome
pituitary pars intermedia dysfunction
exogenous corticosteroid administration
pasture-associated
how does hyperinsulinemia cause microvascular damage?
activation of complement and platelets
what are some common disorders associated with sepsis/SIRS?
gastrointestinal disease
pneumonia
metritis
grain overload
what is the least common type of laminitis?
supporting limb laminitis
who does supporting limb laminitis occur in?
patients with painful musculoskeletal conditions
are radiographic or structural changes evident during the acute phase (first 72 hours) of laminitis?
no
what are some hoof-associated changes in laminitis (on exam)?
elevated digital pulses
hoof warmth
sensitivity to hoof testers
altered hoof appearance
what might be necessary to take radiographs in a painful patient?
local anesthesia
where is contrast injected for a digital venogram?
palmar digital vein
what are the three prongs to treating laminitis?
biochemical support
analgesia
treat underlying cause
what can you do during the acute phase to promote load-sharing by recruiting the solar surface?
soft bedding
deformable/impression material
removable boots with an insert
what is a surgical treatment for biochemical support?
deep digital flexor tenotomy
what side effects are we worried about with horses on NSAIDs?
nephrotoxic
damaging to GI tract
what can opioids do that may predispose horses to colic?
decrease gastrointestinal motility
how is oral bioavailability of gabapentin in horses?
poor: 16%
what effects does lidocaine have?
analgesic
anti-inflammatory
what temperature should the hoof be below to achieve effective hypothermia in digital cryotherapy?
10 degrees C
where does growth begin of the epidermis?
coronary segment
what makes up the two-layered stratum germinativum?
cells of stratum basale migrate into stratum spinosum
what are the layers of hard keratins in the stratum corneum?
stratum externum
stratum medium
stratum internum
what does the stratum internum feature?
featured epidermal lamellae: primary and secondary
what provides the critical connection between the hoof wall and the distal phalanx?
dermal papilla interdigitate with epidermis: primary and secondary dermal lamellae
what is the terminal arch?
anastomosis in solear canal of palmar digital arteries and veins
where does the dorsal branch of the palmar digital nerve innervate?
dorsal 1/3 of hoof
what forces act upon the digit?
weightbearing
support of frog and sole
pull of deep digital flexor tendon
lamellar attachments
pull of extensor tendon
is endocrinopathic laminitis inflammatory?
no
what does insulin do in endocrinopathic laminitis?
activates insulin-like growth factor-1 receptor
mitosis lamellar cells
dysregulation cellular adhesions
how does sepsis/SIRS cause laminitis?
injury to basement membrane: separation of dermal and epidermal lamellae
what causes loss of lamellar cellular adhesions in supporting limb laminitis?
protracted alteration in weightbearing leads to decreased perfusion of food and decreased oxygen/nutrients
ischemia and negative energy balance
where is sensitivity to hoof testers most common with laminitis?
toe region
which radiographic views are taken for laminitis?
lateral-medial
dorsal-palmar/plantar
+/- dorsoproximal-45 degree palmaro/plantarodistal oblique
why is heel elevation useful in treatment?
decreases tension from deep digital flexor tendon on dorsal laminae
decreases compression of solar corium and circumflex artery
why is a rocker component of a shoe useful?
allows patient to adjust breakover
what are the indications for deep digital flexor tenotomy?
continued rotation of distal phalanx
progressive/persistent vascular deficits in venogram
no hoof growth despite mechanical intervention
what are the non-selective COX inhibitors?
phenylbutazone
flunixin meglumine
how does gabapentin work?
mimics neurotransmitter GABA
what can ketamine be combined with?
alpha-2 agonist
opioids
lidocaine
what can lidocaine be combined with?
alpha-2 agonist
opioids
ketamine
what is the duration of bupivacaine (abaxial sesamoid perineural block)?
120-240 minutes
what can be used in an epidural?
local anesthetic
opioid
alpha-2 agonist
what effects does digital cryotherapy have?
vascular effects
analgesic effects
anti-inflammatory effects
metabolic effects
