Laminitis Flashcards
What are 3 causes of laminitis?
- Systemic inflammatory disease
- Endocrine disease
- Trauma
The typical clinical syndrome of laminitis is not observed in what age group of horses?
Why?
- Less than 1 year of age
- Lighter in weight
Is laminitis considered a primary or secondary disease?
Secondary disease
Laminitis is often highly associated what condition?
SIRS
In practice, what is the most commonly reported association?
Endocrinopathies
What are 4 possible endocrine-related causes of laminitis?
- PIPD
- IR (insulin resistance)
- EMS (equine metabolic syndrome)
- Steroid administration
What are 4 laminitis-predisposing phenotypes?
- Obesity
- Insulin resistance
- Hyperinsulinemia
- Mild hypertriglyceridemia
What is a kind of tree that should not be used as bedding for horses?
Black Walnut
What starts the inflammatory process associated with sepsis?
The infiltration and migration of leukocytes (neutrophils).
What are 5 examples of inflammatory mediators?
- IL-1
- IL-6
- CXCL1
- MMP-2
- MMP-9
What does MMP stand for?
Matrix metalloproteinases
What is released from basal membrane cells and becomes active in response to acute disease?
What else can activate them?
- Metalloproteinases
- Bacterial proteases
What is the initial change seen with the vascular theory of laminitis?
What does this lead to?
- Initial vasoconstriction
- Hypoxia/ischemia
Components of what 3 conditions can contribute to the development of cell damage/destruction?
- Reperfusion
- Compartmental syndrome
- Localized DIC
What, in the face of normal glucose levels, can lead to laminitis?
Insulin Resistance or High Insulin
What does insulin resistance or high insulin do to glucose locally?
Disrupts glucose metabolism locally.
Exacerbation of what may precede the onset of clinical laminitis in susceptible animals?
Insulin resistance and hyperinsulinemia
How does excessive insulin affect the hooves?
Glucose dysregulation at lamellar epithelial cell level.
What does disturbances in vascular function cause in the hoof?
Makes them more susceptible to other vascular events.
What are 2 other conditions insulin resistance tends to be related to?
- Obesity
- Chronic inflammatory state
What does lamellar hypoxia lead to?
Up-regulation of MMPs.
What are the 3 major forces involved with laminitis?
- Shear forces
- Vertical forces
- Tensile forces
What is playing a critical role, contributing to amount of other forces repercussed on foot?
Vertical load
What are 2 factors contributing to the vertical load placed on a hoof?
- Weight of horse
- Size of hoof
Rotational displacement is attributed to what type of forces?
Tensile forces
Where do the tensile forces originate from?
Deep digital flexor
Where do the shearing forces originate from?
Leverage of dorsal hoof wall
Vertical displacement is attributed to what type of forces?
Shear forces
The shear forces causing vertical displacement result in what 2 types of movement?
- Hoof wall up the limb
- Sole into the ground
It is important to make sure the toes don’t get too what with laminitis?
Too long
What needs to be done first with a suspected case of laminitis?
Complete physical exam with specific evaluation of the hooves.
What are 5 aspects of evaluating the hooves for laminitis?
- Stance, gait
- Heat, swelling, digital pulses in multiple feet
- Palpation of coronary band
- Hoof tester response to DDF
- External hoof exam
Where in the hoof will you see a response from a hoof tester if laminitis is present?
Responsive in the toe
What is the most subtle/sensitive clinical sign for laminitis?
Weight shifting
What can be used to show increased weight shifting?
Pedometer
Pedometers can pick up weight shifting an average of how much earlier before other clinical signs of laminitis?
2-4 hours
Horses with laminitis will sometimes take up what type of stance?
Tripod stance
What type of a gait might horses with laminitis have?
Walking on eggshells
What arteries are used for digital pulse evaluation?
- Posterior palmar digital artery
- Posterior plantar digital artery
Where are 2 locations digital pulses are felt for?
- Abaxial sesamoid area
- Mid-low pastern
An obvious indentation at the level of the coronary band and indicate what?
Sinking
With severe laminitis, detachment can be seen in what part of the hoof?
White line
What is one diagnostic technique that can be used for rotational evaluation of laminitis?
X-ray
The distance between the outside hoof wall and the dorsal surface of P3 should be less than what in a normal horse?
18 mm
Increasing distance between the outside hoof wall and the dorsal surface of P3 indicates what?
Rotation
What are 3 possible causes of a radioluscent density on a radiograph looking for laminitis?
- Air
- Serum
- Hemorrhage
A radioluscent density on a radiograph between the outer hoof wall and P3 shows what?
Detachment
What are the 4 stages of laminitis?
- Developmental
- Acute
- Sub-acute
- Chronic
Which stage of laminitis has no clinical signs?
Developmental
Which stage of laminitis has clinical signs but no mechanical disruption?
What is the time frame for this stage?
- Acute
- 72 hours or less
What is the third stage of laminitis?
How long might it take?
- Sub-acute
- Weeks to months
Which stage of laminitis has clinical signs with mechanical disruption?
This can take place as soon as when?
- Chronic
- Within 24 hours
What are 3 exam findings that can indicate laminitis?
- History
- Signalment
- Clinical signs
What are 3 types of clinical signs that can indicate laminitis?
- Stance
- Gait
- Foot
What are 2 diagnostic procedures that can be used to diagnose laminitis?
- Hoof tester evaluation
- Radiography
Where are 3 locations to place marker for a laminitis radiograph?
- Dorsal hoof wall
- Tip of frog
- Coronary band
Which radiographic hoof marker us used in the determination of rotation of P3?
Dorsal hoof wall
A thumb tack at the tip of the frog can be used to determine what?
Specific location of P3 with respect to external landmark in hoof.
What type of a shoe is used for laminitis?
Heart bar shoes
What is a marker at the coronary band used to evaluate?
Distal displacement in the hoof.
What are 2 types of scoring systems used to evaluate lameness associated with laminitis?
- Obel scoring system
- Clinical scoring system
What are 2 things that have been used to identify perfusion deficits?
If perfusion deficits are present, this usually indicates what?
- Digital venogram and vascular perfusion casts
- Indicates poor prognosis
What are 2 treatment generalities to consider with laminitis?
- Address systemic nature of the disease
- Specifically treat the feet
What are 2 aspects to treating the inciting disease?
- Address the localized problem
- Systemic disease treatment
What is a way to specifically address the feet?
Cryotherapy
When should cryotherapy be applied?
Throughout the developmental period.
What is the best choice of cryotherapy to apply?
Ice and water immersion
What are 3 drugs that can be used to promote digital perfusion through vasodilation?
- Acepromazine
- Isoxuprine
- Nitroglycerin
What are 2 general ways to limit the damage of laminitis?
- Systemic pharmacotherapy
- Local support therapy
What are 3 categories of drugs that can be used systemically for laminitis?
- Anti-inflammatories
- Analgesics
- MMP inhibitors
What is a drug that can be given CRI to help limit the damage of laminitis?
Lidocaine
Lidocaine decreases the production of what two things?
- Chemokines
- Inflammatory mediators
What are 2 forms of local support that may help limit the damage of laminitis?
- Bedding
- External application of support to hoof
Will laminae reattach once they have been separated?
No
What are 3 ways to provide local foot therapy to treat laminitis?
- Support
- Reduce stresses
- Return normal relationship between P3 and hoof
What is a type of pad that can be used for hoof support with laminitis?
What else can be used that might be handy?
- Lilly pad
- Gauze roll
What color Styrofoam has the right consistency to be used as a hoof support for laminitis?
Pink
What does EDSS stand for?
Equine digital support system
What are 3 things an EDSS incorporates?
- Frog support
- Wedge
- Easier break over
What is a Redden Ultimate?
Support option for laminitis.
What can be done with the toes of a laminitic horse?
Trim and roll the toe.
What are 2 things to be avoided with a laminitic horse?
- Avoid shoes and nails
- Avoid moving the horse if they don’t want to move
What are 2 ways to achieve a “roller toe” in a laminitic horse?
- Trimming and shaping hoof directly
- Applying shoe
What is an alternative to nails?
Toe clips
What is an option reserved for more severe cases of laminitis?
Deep digital flexor tenotomy
What are 4 indications for a DDF tenotomy?
- Rotated more than 12 degrees in first 30 days
- Extensor process distal 1 cm in first week
- Unresponsive
- Chronic where other methods unsuccessful
What is a specific type of shoe used for laminitis?
Heart bar shoe
How does the functional outcome of laminitis correlate to the degree of rotation or distal displacement of P3?
It does not correlate.
What does functional outcome correlate to?
Clinical grade
Laminitic horses with what are more likely to die?
Distal displacement
