Laminitis Flashcards
(34 cards)
Normal lamellae
basal epithelial cells tightly adhered to each other and BM
Cytoskeleton anchors a cell to its neighbours
Lamellae in acute laminitis
Epithelial cell stretch (endocrinopathic)
Epithelial cell loss of adhesion
BM detachment (sepsis related)
disturbance of lamellar attachment between hoof and bone
Two types of laminitis
One- can affect any horse
- endotoxin/sepsis
- weight bearing
Two - endocrinopathic
Pathogenesis of weight bearing laminitis
Lack of limb load cycling activity
Interferes with the usual perfusion of lamellae
Ischaemia and dysfunction of cells
Excessive load bearing results in acute laminits in the supporting limb
Acute severe unmistakable signs
Endocrinopathic laminitis
Affects a particular type of horse or pony
Usually old, unfit, obese, non-native types
Most common type of laminitis
Mild and insidious onset
Slow progressive lengthening of lamellae caused by stretch and cellular proliferation
Clinical signs of acute laminitis
Reluctance to move
Increased recumbency
Stiff, shortened gait
Rocking backward stance
Facial grimacing
Signs of acute laminitis on clinical exam
Hot hoof walls
Divergent rings
Increased digital pulses
Tight muscles
Tachycardia
Sweating
Increased resp rate and effort
Signs of sub-clinical laminitis
Divergent rings - horizontal lines wider apart at the heel than toe
Flat soles
Dropped soles
Widening white line
Footsore after trimming
Differential diagnoses of lying down, sweating, tachycardia
Laminitis, colic, foaling
Differential diagnoses of stiff gait, reluctance to move, tight muscles
Laminitis
Exertional myopathy
Atypical myopathy
Neurological diseases
Differential diagnoses of increased resp rate and effort
Laminitis
Equine asthma
Weight distribution of horses
FL 60%
HL 40%
Treatment of the condition underlying laminitis
Insulin regulation
- metformin
- strict dietary change
Sepsis
- antibiotics
Treatment to minimise ongoing lamellar damage
Anti-inflammatories
- NSAIDs (phenylbutazone, flunixin, meloxicam)
Confinement
- Box rest
- Sedation (ACP)
Adverse consequences of NSAID use in horses
GI disease
- glandular disease in stomach
- colitis
Kidney injury
Check bloods after 7-10 days
- Albumin
- Creatinine
- SDMA
Other analgesic drugs that can be used
Paracetamol - acetiminophen
- Useful alongside NSAIDs
- Use pracetam (licensed for pigs)
Fentanyl patches
- Very expensive
- not been tested in donkeys
If hopitalised
- lidocaine CRI
- Morphine
- Super-combination CRIs
Mechanical foot support for laminitis
Put putty on caudal 1/3 of foot
Tape on a solid pad then put foot down
Conservative trimming to facilitate breakover
Steward clogs (orthotic foot support) - needs to be on both feet, reduce shearing forces
AND
Bedding - shavings
When can you put on putty for mechanical support of the foot?
As soon as you can pick the foot up for a few secs, or whilst recumbent.
Do it in stages over 30 mins - better tolerated
Method of applying foot putty for mechanical support
Impression material to the caudal 1/3 of the foot only
Tape on a solid pad then put the foot down (impression material needs to set)
Remove pad, trim to heel, apply foam pad over the top and tap in place
Continuous digital hypothermia in laminitis treatment
Slows progression of acute laminitis - even in sepsis
Monitoring progression of laminitis
Clinical exam
Check sole for prolapse
Check coronary band for sinking
Radiography
Radiographs for laminitis monitoring
Lateromedial view
Dorsopalmar view
Check all four feet
Stand square on blocks
Normal distances/proportions of horse hoof
Coronary extensor distance: -2-15mm
Hoof capsule:hoof width ratio: 50-65%
Hoof width: 14-22mm
Sole depth: >11-15mm
Hoof thickness: DP length ratio: <30%
Dorsal hoof wall angle: 48-54%
Parietal surface angle: 0-2 degrees < dordal hoof
Solar margin angle: 3-8 degrees
Normal coronary extensor distance
-2 - 15mm
