Term
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Definition
| Papillae are the finger-like projections that connect the basement membrane of the dermal-epidermal junction to the periosteum. |
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Term
| ____________ lamellae are affected in laminitis. |
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Definition
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Term
| The hoof capsule starts at the _____________ corium and works its way down. |
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Definition
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Term
| What bone is suspended within the hoof capsule? |
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Definition
| Coffin bone (distal phalanx) |
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Term
| Growth of the hoof capsule begins in the _____________ from epidermal cells, with a cell division every ___ hours. It takes approximately ________ months for the epidermal cells to reach the ground. Hoof remodeling is under the control of ___________________, which control the breakdown and formation of bonds. |
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Definition
Coronary corium
8 hours
8-12 months
Metalloproteinases (2 and 9, specifically) |
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Term
| Development of laminitis occurs when there is disruption of the supportive apparatus at the bone (corium/dermal lamellae)--Hoof (epidermal lamellae) junction, also known as the ___________________________. |
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Definition
| Lamellar basement membrane zone |
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Term
| What three clinical disturbances occur from the crushing of arteries, veins, and nerves of the hoof at the lamellar basement membrane zone? |
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Definition
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Term
| T/F: the severity of laminitis severely correlates with histological changes. |
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Definition
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Term
| List some "trigger factors" for laminitis development: |
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Definition
Colitis (endotoxemia, CHO overload)
Metritis/retained placenta
Abdominal/thoracic infection
Endocrinopathies
Concussive forces (road founder)
Supporting limb laminitis
Black walnut toxicity/S. bovis (in bedding) |
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Term
| Describe the association between endocrinopathies and laminitis development. |
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Definition
The adhesion between epidermal lamella and the basement membrane (hemidesmosomes) are highly dependent on glucose. Glucose starvation leads to hemidesmosome release.
Glucose starvation (decreased use of glucose in the tissues) occurs with Cushing's disease and insulin resistance. |
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Term
| Describe the inflammatory theory for laminitis development: |
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Definition
| WBC activation-->inflammatory mediators -->SIRS and MODS-->septicemia |
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Term
| Describe the vascular theory for laminitis development: |
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Definition
Disruption of blood flow (toxins, endothelin/platelet activation, dermal-epidermal necrosis)
Possibility that this leads to local hypoglycemia, edema, and swelling |
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Term
| T/F: restricting blood flow limits the development of laminitis. |
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Definition
| True: decrease concentration/time exposed to trigger factors |
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Term
| List the 4 theories/pathophysiologies of laminitis development: |
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Definition
Inflammatory
Vascular
Enzymatic/Metabolic
Pain |
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Term
| T/F: irreversible changes have likely occurred by the time a horse shows clinical signs of laminitis. |
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Definition
| True--can affect all four feet, one foot, or just the front feet |
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Term
| What are the clinical signs of a horse presenting with laminitis? |
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Definition
Reluctance to move, especially turning/hard surfaces
Shifting weight when standing--hindlimb loading, lying down |
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Term
| What are the signs of acute laminitis? |
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Definition
Warm hooves, increased digital pulses
Tachycardia, muscle tremors, sweating (if severe)
Sole pain and dorsal percussion on hoof testers
Reluctant to lift limbs |
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Term
| Chronic laminitis is any laminitic case presenting with > _____ days duration. |
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Definition
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Term
| Chronic laminitis is manifested by what structural changes? |
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Definition
Displacement of the coffin bone
Convex sole in front of frog apex
Divergent growth rings
Flattened sole with widened white line |
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Term
| What are the various displacements of the the coffin bone that can occur with chronic laminitis? |
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Definition
Rotation
Sinking
Of the two, sinking is the worst
Both changes are due to mechanical forces |
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Term
| Diagnosis of laminitis is based on _______________ and ________________. |
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Definition
Clinical signs
Radiographic evidence |
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Term
| T/F: it is better to assume a horse has laminitis than spend too much time running diagnostics to determine another cause. |
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Definition
|
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Term
| What are some rule outs for laminitis? |
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Definition
| Hoof abscess, muscle disorders |
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Term
| When treating laminitis, it is especially important to treat the _________________. |
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Definition
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Term
| What are the therapeutic options for acute laminitis? |
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Definition
Stabilize/reduce mechanical forces: no exercise, deep bedding/sand, frog/sole support bandages or shoes
Anti-inflammatories
Cryotherapy
Vasodilation (questionable--only during chronic?)
DMSO
Perineural analgesia |
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Term
| When performing a perineural analgesia for treatment of acute laminitis, the __________________ block is most effective because the ____________________ block misses the dorsal hoof wall. |
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Definition
Abaxial sesamoid most effective
Palmar digital misses the dorsal hoof wall |
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Term
| T/F: the use of a lily pad is a good choice in a horse with no weight bearing limbs, as it reduces shearing forces. |
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Definition
| False; only good if there is a weight bearing limb and shearing forces will still be present. |
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Term
| Describe the blueboard styrofoam procedure for emergency laminitis support: |
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Definition
Place for 24-48 hours, then trim toe, then place second support
Temporary |
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Term
| Client compliance is key with laminitis therapy, as treatment can sometimes exceed ____________. |
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Definition
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Term
| If rotation of P3 is > ______ degrees, then a ____________________________ may be indicated to help remove the rotational force of the ____________________. However, the prognosis for this procedure is guarded to poor. |
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Definition
10-15 degrees
Deep digital flexor tenotomy
Deep digital flexor tendon |
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Term
| What is the prognosis for laminitis? |
|
Definition
Controlled pain/no displacement: good
Displacement: guarded
15 degree rotation: poor
Sinking displacement: poor |
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