Laminitis

Question 1

Normal lamellae

Answer 1

basal epithelial cells tightly adhered to each other and BM

Cytoskeleton anchors a cell to its neighbours

Question 2

Lamellae in acute laminitis

Answer 2

Epithelial cell stretch (endocrinopathic)

Epithelial cell loss of adhesion

BM detachment (sepsis related)

disturbance of lamellar attachment between hoof and bone

Question 3

Two types of laminitis

Answer 3

One- can affect any horse
- endotoxin/sepsis
- weight bearing

Two - endocrinopathic

Question 4

Pathogenesis of weight bearing laminitis

Answer 4

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

Question 5

Endocrinopathic laminitis

Answer 5

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

Question 6

Clinical signs of acute laminitis

Answer 6

Reluctance to move
Increased recumbency
Stiff, shortened gait
Rocking backward stance
Facial grimacing

Question 7

Signs of acute laminitis on clinical exam

Answer 7

Hot hoof walls
Divergent rings
Increased digital pulses
Tight muscles
Tachycardia
Sweating
Increased resp rate and effort

Question 8

Signs of sub-clinical laminitis

Answer 8

Divergent rings - horizontal lines wider apart at the heel than toe
Flat soles
Dropped soles
Widening white line
Footsore after trimming

Question 9

Differential diagnoses of lying down, sweating, tachycardia

Answer 9

Laminitis, colic, foaling

Question 10

Differential diagnoses of stiff gait, reluctance to move, tight muscles

Answer 10

Laminitis
Exertional myopathy
Atypical myopathy
Neurological diseases

Question 11

Differential diagnoses of increased resp rate and effort

Answer 11

Laminitis
Equine asthma

Question 12

Weight distribution of horses

Answer 12

FL 60%
HL 40%

Question 13

Treatment of the condition underlying laminitis

Answer 13

Insulin regulation
- metformin
- strict dietary change

Sepsis
- antibiotics

Question 14

Treatment to minimise ongoing lamellar damage

Answer 14

Anti-inflammatories
- NSAIDs (phenylbutazone, flunixin, meloxicam)

Confinement
- Box rest
- Sedation (ACP)

Question 15

Adverse consequences of NSAID use in horses

Answer 15

GI disease
- glandular disease in stomach
- colitis

Kidney injury

Check bloods after 7-10 days
- Albumin
- Creatinine
- SDMA

Question 16

Other analgesic drugs that can be used

Answer 16

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

Question 17

Mechanical foot support for laminitis

Answer 17

Put putty on caudal 1/3 of foot
Tape on a solid pad then put foot down

OR

Steward clogs - reduce shearing forces

AND

Bedding - shavings

Question 18

Continuous digital hypothermia in laminitis treatment

Answer 18

Slows progression of acute laminitis

Question 19

Radiogrpahs for laminitis monitoring

Answer 19

Lateromedial view
Dorsopalmar view

Check all four feet
Stand square on blocks

Question 20

Normal distances/proportions of horse hoof

Answer 20

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

Question 22

Radiology of laminitic cases

Answer 22

Degree of rotation does not determine likely return to athletic performance

Even >11.5 degrees dorsal rotation has been shown to return to previous use

Distal displacement of P3 considered poor prognostic indicator