Laminitis Flashcards
What is the definition of laminitis
Inflammation of the soft tissue laminae of the hoof
***systemic dz commonly endocrine
Most commonly the front feet are affected
What other term can be used for chronic laminitis
Founder
Experimentally the classic model for predictable development is based on what model?
The carbohydrate overload model
Original grading system (obel)
MANY other etiologies are involved in the causes of laminitis but thought to have a similar pathophysiologic basis
What are MMPs
Matrix metalloproteinases they see responsible for directed controlled detachment of the laminae required for growth of the hoof
PROBLEM if there are triggered for excessive uncontrolled activation
What is the insulinopathy theory have to say?
It believes there may be an association of hyperinsulinemia and laminitis. Speculating that hyperinsulinemia sensitized the structures in the hoof
Glucose metabolism physiologically dysfunction thought to be central in mechanism.
Hyperinsulinemia also results in vascular dysfunction as well as inducing SIR which could contribute to the inflammatory mechanism
What are the major forces involved in mechanical displacement
Vertical load, shear forces, tensile forces, and solar fulcrum
*** dominant factor is likely vertical load weight of the horse and small hoof
What is rotational displacement?
What are some ways you could fix?
Force from the deep digital flexor and leverage of hoof wall
-tensile forces pull of ddf
Lack of sufficient dorsal hoof dermal epidermal allows for displacement
Heel vs toe growth rate *heel growing faster
You could wedge shoe
Cut deep digital flexor NO LONGER PERFORM
What is vertical displacement?
Prognosis?
Poor prognosis
Associated with damage to the entire foot
Shear forces- loss of laminar support such that vertical load imposed on the foot predominates FORCING the hoof wall up the limb and sole into the ground *no opposing force
P3 in normal position
Can “walk out of hooves”
What is the presenting complaint in a laminitis case?
Lameness and reluctance to move
What is the stance you would see if front limbs are involved?
What if all four limbs?
What if one limb?
Front legs have prayer stance with all the weight on the back limbs
All four limbs effected have all four limbs underneath
One limb REALLY rare could be one is more severely effected but most likely a fracture
What are the four major things that are going to lead you to diagnose a laminitis case?
Digital pulses- typically strong bounding pulse symmetrical medial and laterally
Elevated hoof temperature- very warm
Coronary band- can see swelling and edema ***sinking evidence
Pain- hoof testers pain at the toe if penetrating sole often see hemorrhage in semi circular pattern
Why is xrAy important?
Markers?
Most important technique for evaluating coffin bone position with respect to hoof *prognosis/severity
Reevaluate on a regular basis
Markers- evaluate 2 views >important is the lateral
Typically mark the dorsal surface of the hoof wall
-evaluate rotation
Mark the tip of the frog -relation of coffin bone with tip of frog >heart bar shoe
Mark distal aspect of pattern -horizontal displacement of coffin bone *sink and evaluate proximal limit of extensor process
Describe how you would know a horse was in the developmental stage of laminitis
Prior to the development of clinical signs (endotox, colic etc)
GOAL is to prevent development
Tx start icing the feet to decrease cell metabolism
How do you know a horse is classified in the acute phase of laminitis
First identifiable signs ***ends if one of the two events happen
1 passing of 72hrs without xrAy evidence of mechanical disruption
2 development of digital collapse * can happen as soon as 24hrs
GOAL limit the severity
How do you know you are in the subacute phase of laminitis
Duration varies typical 8-12wks
Hoof is healing but still very weak and can still structurally fail
*full recovery is likely
GOAL of intervention protect in order to limit progression to chronic
How do you know you are in the chronic phase?
Dun dun duuuuuuun
Mechanical disruption IRRESPECTIVE of duration
Includes both rotational displacement and vertical
Horses in this phase may NEVER recover
This phase is associated with vascular insuf localized sepsis metabolic growth dysfunction
GOAL rehabilitation
What are your four goals of treatment of laminitis
1-staging
2-treat inciting dz support feet max use of others DO NO HARM
3 PAIN CONTROL
-antiinflammatories sys NSAIDS
-limit edema with DMSO
-promote vasodialation NITROGLYCERIN
-limit damage and progression flunixin, endoserum, POLYMIXIN b
What is one treatment that is CONTRAINDICATED in laminitis?
Steroids *potentiate vasoconstriction associated with shock and stress
What are the three main causes of laminitis
Endotoxemia
Endocrine disorders
Trauma
