Laminitis Flashcards
What is laminitis?
Inflammation of the lamellae of the inner hoof capsule
*painful and debilitating condition
What are the common organ systems that can be involved with laminitis?
GI Respiratory Reproductive Endocrine Musculoskeletal Integumentary Immune system Renal
What are risk factors for laminitis ?
Endotoxemia/sepsis Endocrinopathies Trauma “road founder” Drug induced Toxin induced
How does systemic disease cause laminitis?
Lamellar tissues are exposed to inflammatory factors that leads to disorganization of the lamellar anatomy
Poor blood supply -> hypoxia
Inflammatory cells
Bacteria
Imbalance in glucose metabolism
How doe leukocytes contribute to laminar damage ?
Production of ..
Cytokines and matrix metalloproteases (MMP) and ROS
MMP can degrade ECM proteins
What is the vascular hyothesis for development of laminitis?
Poor perfusion and ischemia due to vasoconstriction
Swelling in response to inflammation —> compartmental syndrome (encapsulated within the hoof)
Reperfusion injury -> post vasoconstriction return of blood -> production of free radicals contribute to cellular injury and inflammation
T/F: laminitis can be caused by hyperglucosemia
False
Can be induced by hyperinsulinemia
How can trauma lead to laminitis?
Tearing of sensitive tissue
Vasospasm
Fatigue and vasocompression
T/F: foals can get laminitis
True
Very rare
Usually due to loss of blood supply to the distal limb—> salmonellosis or thrombosis
Why do you usually see laminitis on the front feet before the hind feet?
Front feet carry 60% of the horses weight
What are the biomechanical forces acting on the hoof?
Weight of horse (down)
Force of ground (up)
DDF tendon (upward on plantar/palmar surface)
Lamina perpendicular to hoof)
Extensor tendon (upward on dorsal surface)
What are the two types of displacement that can occur in laminitis?
Rotational
Vertical
Horse is shifting weight from one foot to the other, but moves relatively freely.
What grade is this?
Grade 1
Horse has obvious lameness, when Turing has an stilted gait and shuffles. One foot can be raised without causing extreme discomfort in the contralateral foot.
What grade is this?
Grade II
Horse is reluctant to move and resists any attempt to lift a foot
What grade is this ?
Grade III
Horse is immobile and often recumbent. What grade of laminitis is this?
Grade IV
The distance from the hoof wall to the edge of the 3rd phalanx is usually _________mm, if larger it usually means swelling is present
18
What are the phases of laminitis??
Developmental phase
Acute - first sign of pain (clinical foot pain and lameness)
Chronic - compensated (stable)/ uncompensated (unstable)
What is the treatment for the developmental stage of laminitis?
Treat primary cause
Cryotherapy
What are the drug therapies for acute laminitis ?
NSAIDS- phenylbuatzone, flunixin meglumine, previcox
Butorphanol
Lidocaine
Morphine
Ketamine
DMSO
Pentoxifylline
Atropine
What are the treatment options for laminitis at the hoof level?
Decreasing the tension of the DDF on the coffin bone
Unloading the laminar interface
Reduce inflammation
Easing break over
Protecting sensitive tissue
What factors do you take into account for prognostic indicators in laminitis
Amount of lamellar damage (sinkers) Hoof conformation Duration (bone reabsorption and infection) Coronary band damage (shear lesions) Vascular damage
What is the difference between an chronic compensated and chronic uncompensated laminitis?
Compensated - coffin bone has displaced but stabilized to some degree, hoof growth if often slowed or distorted
Uncompensated- coffin bone continues to displace
