Equine Med- Laminitis

wilsbach's version from 2016-03-02 02:23


Question Answer
what is the #1 cause of death in horses?...COLIC. LOL. But laminitis is #2
so what/where is the laminae of the hoof?
what is the tiny anatomy of the laminae like?
what IS laminitis?Inflammation of the laminae! Due to many causes which Ultimately lead to similar process, Variable severity and phases
explain the basic steps of the process which go from the beginning to coffin bone rotation of laminitisInflammation → instability → pain and mechanical failure of laminae → coffin bone movement (and it is very difficult to correct bone movement)
what are the 3 phases of laminitis, and how are they identified as such? At which stage do treatments work best?(1) Developmental: No clinical signs- treatments work best here! (2) Acute: Onset of clinical signs (3) Chronic: Radiographic changes
what are some names and conditions associated with chronic laminitis? Long term= “Founder” rings, “slipper toe,” chronic foot abscesses/white line disease
mild lam. clinical signs? Moderate? Severe?MILD: Short gait, leaning back but willing to walk. MOD: Weight-shifting, reluctance to walk . SEVERE: Cannot hold up one leg, unable to walk
(said in class) possible ddxs for standing funnyddx for standing funny: just ferriered, colic, neuro signs, or tying up (active rhabdomyolysis) or 1* mm disorders etc...
what is the most common form of laminitis (bilat, unilat, front, back?)bilateral forelimb is most common presentation but can have basically combo
why do horses lean back when they have laminitis?pain in toe, so lean back to take weight off toe
how will laminitis present on PE?Heat in hooves, bounding digital pulses, Painful (unwilling to pick up feet), if chronic - abnormal hoof conformation
what will a hoof tester test reveal if there is laminitis? Sensitive over the toe.
what if you can't pick up their foot for a hoof tester test?tap the dorsal wall of the hoof with it- see if they react
# R/O for non-weight bearing lameness? How can you tell it is this?solar abscess. (unilateral inc pulse)
how will rads look like with laminits?thickening of the dorsal hoof wall, rotation or sinking of coffin bone, gas lines, remodelling of coffin bone in chronic cases. (can see a gas line sometimes too- separation or bact infxn)
if a horse presents acutely for a laminitis, what will you see on rads?might not see anything, but gives you a baseline to work with
what do Contrast venograms tell you about laminitis/what do you eval with this? To evaluate blood supply.. Can use as a prognostic tool (laminitis= not nearly as much blood flow)
what are the 4 categories of causes of laminitis?(1) Endocrinopathies (2) Systemic Inflammatory Response Syndrome (3) Support limb (4) Repetitive trauma
ANY underlying cause of laminitis leading to laminitis can be made worse by what 2 management practices?*All made worse by obesity & poor hoof care*
what are 3 endocrinopathies which can lead to laminitis?(1) Equine Metabolic Syndrome (2) PPID (Equine Cushings-like Syndrome) (3) *Corticosteroid administration
Systemic Inflammatory Response Syndrome can cause laminitis-- what are 3 conditions which can lead to this inflammatory response?(1) Grain overload (2) Colitis/Anterior enteritis/Strangulating GI lesions (3) Retained placenta
of the four main causative reasons for laminitis, which problem is the MOST common reason for laminitis to occur? Endocrinopathies!!
Equine Metabolic Syndrome and PPID (Equine Cushings-like Syndrome) can lead to laminitis-- what are some predisposing factors to developing these? which 2 main hormonal disturbances result in the laminitis?Breed/Genetic predilection! Diet and exercise also can predispose. Hyperinsulinemia / Hypercortisolemia are the main problems which lead to Metabolic epidermal dysplasia --> Secondary inflammation
explain how Hyperinsulinemia / Hypercortisolemia (think of what two conditions?) can cause laminitis (pathway)(think equine metabolic syndrome and PPID) the hyperinsulin and hypercortisol disrupts metabolism in how vessels use glucose-- jacks up how they fxn, since cellular metabolism is screwed up, you get epidermal dysplasia (laminae pull apart from each other) and causes compression of millions of BVs in there--> necrosis-->inflammation
what is this "pasture associated laminitis" thing?fresh pasture grass is high in sugar-- too much glucose--> hyperinsulinemia (see other card for more)
what drug can basically cause an iatrogenic endocrine based laminitis?Corticosteroid induced
explain how insulin resistance can lead to laminitis (3 factors which contribute to insulin resistance are?)INSULIN RESISTANCE can be caused by genetics, obesity, and PPID. Insulin resistance lowers the laminitis threshold (since insulin and glucose affect BV cellular metabolism)
Systemic Inflammatory Response Syndrome-- what are the things which usually trigger the systemic inflammatory response?Endotoxins/cytokines/inflammatory mediators.
What IS SIRS/ systemic inflammatory response syndrome? most common reasons this happens?This is a response to circulating toxins. They usually originate in GI tract (can be from colic but not all colic= SIRS or endotoxemia), but the toxins can come from repo/resp system too. Individual horse sensitivity to toxins play a role in the response--will they go into systemic shock? and perfusion/blood pressure/presence of a cytokine storm all play a role
PE sign of endotox in horse?purple line around gums
how does systemic inflammation in SIRS (systemic inflammatory response syndrome) lead to laminitis?Systemic inflammation means inflammation are in lamellae too--> cell dysadhesion
how long can the gap be between when SIRS happens and when acute signs of laminitis develop? When will you see strauctural changes?systemic inflammation can occur hours before clinical signs! But structural changes wont occur till later
what are like the 3 most common reasons for SIRS (systemic inflammatory response syndrome) to develop?(1) severe GI inflammation (colitis, AE aka anterior enteritis aka angry small intestine) (2) strangulating lesions (3) Retained placenta (remember standing in 1 hr, nursing in 2, placenta should be out in 3)
Individual variation of response to SIRS (systemic inflammatory response syndrome) might depend on what?might be Linked to gut microbiome?
explain "support limb laminitisIf a horse is Non weight-bearing in 1 limb, then they can't "cycle" putting most of their weight from one limb to the other. That means the support limb never gets a break--> blood flow is compromised--> lack of oxygen to hoof tissues--> laminitis (dysadhesion and necrosis of the delicate laminae!). Secondary Inflammation is basically the problem with this dz- PREVENTION IS ESSENTIAL! (ice/support other limb)
Disease progression of laminitis Depends on a number of factors, such as...Severity, cause, Individual variability (ie the horses predisposing factors), and the Phase in which treatment occurs!!!
what phase do you ideally want to tx laminitis in?DEVELOPMENTAL STAGE- but not C/S here so basically prophy tx when appropriate
Disease progression of laminitis: for MILD colic, what are what are rads like? how long should you rest? can they return to work?No radiographic changes!! Lameness and clinical signs resolve within days, but should Rest for a 3-4 weeks. Can then allow Slow return to work
Disease progression of laminitis: for MODERATE colic, what are what are rads like? how long should you rest? can they return to work?Mild radiographic changes, horse should be rested for 4-6 months. Moderate laminitis requires Life-long management. And there is a Possible return to work
Disease progression of laminitis: for SEVERE colic, what are what are rads like? how long should you rest? can they return to work? Significant radiographic changes!! basically game over-- ends athletic career, possibly fatal
What are the 4 mainstays of laminitis treatment, and what should you keep in mind about treatment?Remember that with Tx no one specific tx works! (1) Treat underlying cause (if known) (2) Anti-inflammatories (endocrine/SLL<--supporting limb lameness i think) (3) Hoof support (4) pain control
For endocrine disease associated laminitis, how can you treat this underlying cause to help with the laminitis?Diet & management changes, Medications
For infections/endotoxemia associated laminitis, how can you treat this underlaying cause to help with the laminitis?TREAT the infxn, anti-inflammatory
when is icing the feet of a laminitis pt helpful?only effective if done EARLY in the progression of the dz
what are the 3 mainstays of Anti-inflammatory treatment?(1) Icing feet: Prevention & intermittent pain relief, Only effective EARLY! (2) NSAIDs: Phenylbutazone, Banamine® (Flunixin meglumine), Firocoxib (Equioxx®) (*careful of side effects like RDC etc) (3) Pentoxifylline (xanthine derivative): works as both an Anti-inflammatory & reduced blood viscosity
what are some of the NSAIDs you can use to help tx laminitis?Phenylbutazone, Banamine® (Flunixin meglumine), Firocoxib (Equioxx®) (*careful of side effects like RDC etc)
what is Pentoxifylline? What does it have to do with laminitis?Anti-inflammatory & reduced blood viscosity to help tx laminitis (xanthine derivative)
Tx of laminitis--> Hoof support--> what are the 2 main goals of hoof support?(1) Redistribute weight off the toe to the back of the foot (2) Decrease the breakover
what is breakover? what do we want to do with breakover in laminitis? How would you go about this?Wise says: as a horse walks, the point where they flip their foot over to move forward... Internet says: Breakover begins when the heels leave the ground and start to rotate around the toe of the hoof, which is still in contact with the ground. We want to DECREASE the breakover with laminitis because pressure is being put on the toe which is where the problem is. She says you can you can trim off top of hoof wall, shorten it, less effort. (dont have to fight to push pad over)
2 ways to provide hoof support?(1) hoof is padded (2) Sand or deeply bedded stall to cushion foot
How would you like to provide Pain management for laminitic horse? (general statement)NSAIDs & ice often not enough! Multi-modal pain management is best ...but there are limited options in equine :(
Table with which analgesics work where
(in chart not sure if important) 3 drugs that stop transduction of painNSAIDs, Opioids, Local anesthetics
(in chart not sure if important) 2 drugs which stop transmission of painLocal anesthetics, Alpha-2 agonists
(in chart not sure if important) 5 drugs which cause modulation of the pain signal?Local anesthetics, Alpha-2 agonists, Opioids, NSAIDs, NMDA receptor antagonists
(in chart not sure if important) 3 drugs which alter perception of painGeneral anesthetics, Opioids, Alpha-2 agonists
what are the 4 Opioids you can give horses?Butorphanol, Tramadol, Morphine/Fentanyl
which opioid can you give IM OR as an IV CRI--- and if you give IV, what will you need to do?Butorphanol- if give IV, can't give alone, combine with alpha-2 agonists
what are 2 Alpha 2 agonists you can give to horses?Xylazine, Detomidine
which local anesthetic can you use in horses, are what are the diff ROAs?Lidocaine (IV CRI)
what NMDA receptor antagonists can you use in horses? (ROA?)Ketamine (IV CRI)
what is a Calcium channel agonist you can use in horses? (ROA?)Gabapentin (PO)
for a horse in SEVERE pain, what is an analgesia combo you might wanna consider? CRI of ketamine and lidocaine
if you want to give an epidural for hindlimb stuff in the horse, what combo of analgesics do you use?Lidocaine, xylazine, morphine
what are some other random txs you can do with laminitis?Stem cell treatment, Deep digital flexor tenotomies , Acupuncture , Forced recumbency , Hoof wall resection, coronary band grooving
what is the alternative tx she emphasized in red?stem cell
which tenotomy can you do to try to help lamintitis?Cut DDFT to help stop rotation of P3
The bottom line is, with laminitisTreatments are unreliable with variable response.. PREVENTION IS KEY!
Minimizing endocrine risk factors-- what are some things you can do? Recognize the phenotype! (such as huge neck crest, curly hair, etc). provide good Diet & exercise to reduce weight, give only small amounts of sugars and starches, and carefully monitor grazing time and frequency.
Farrier care is essential in trying to prevention laminitis, because horses need..regular, routine hoof trimming