Acute Laminitis

Question 1

Define laminitis…

Answer 1

Failure for epidermal laminae to attach to dermal laminae

Question 2

What are the risk factors for laminitis?

Answer 2

Sepsis and systemic inflammation
- GI dz, pneumonia, spectic metritis

Endocrine disorders
- PPID, EMS

Mechanical overload
- Lame on one leg, laminitis risk on good leg

Access to pasture

Question 3

What are the three stages of laminitis?

Answer 3

1. Developmental (contact with trigger)
2. Acute (see clinical signs)
3. Resolution or chronic laminitis

Question 4

Explain the inflammation theory of laminitis…

Answer 4

1. Eating too much grass
2. Hindgut carbohydrate overload
3. Systemic inflammatory response that initiates laminitis

Question 5

Explain the ECM degradation theory of laminitis…

Answer 5

1. Inflammatory and/or hypoxic cellular injury
2. Failure of epithelial adhesion molecules (hemidesmosomes)
3. Dysregulation of protease enzymes MMPs
   - Too much breakdown of hoof wall

Question 6

Explain the metabolic disease theory of laminitis

Answer 6

1. Overeating pasture
2. Obesity = too much adipose tissue and insulin resistance increases
3. Adipose tissue-derived inflammatory mediators.

Question 7

Explain the vascular and endothelial dysfunction theory of laminitis

Answer 7

1. Vascular events of laminitis include venoconstriction and laminar oedema
2. Venoconstriction from platelets and neutrophil activation releases 5HT
3. Also ET-1 and mediators of inflammation

Question 8

How do you diagnose laminitis?

Answer 8

Lameness on 2> limbs
Leaning back on heels
Bounding digital pulses
Pain w hoof testers at point of frog
Palpable depression at coronary band
Radiography

Question 9

What are PPID and EMS how do you treat each?

Answer 9

PPID - Pituitary Pars Intermedia Dysfunction
Tx: Pergolide

EMS - Equine Metabolic Syndrome
Tx: Weight loss, exercise to get rid of adipose

Question 10

What are the endocrine tests to diagnose PPID and EMS?

Answer 10

PPID:
Clinical signs
Basal ACTH
Dex suppression test
TRH stim test

EMS
History
Clinical signs
Demonstrate insulin resistance (fasting insulin and glucose)

Question 11

What medication would you prescribe for laminitis?

Answer 11

TREAT ASAP as serious once clinical signs show

Analgesia

a. NSAIDS
- - Phenobutazene
- - Flunixin
- - Carprofen

b. Opiates
- - Morphine
- - Pethadine
- - Fentanyl

Prophylaxis

• • Vasodilator/vasoconstrictors
• • ACP (vasodilate)
• • Ice/water fluid bags tied to limb

Question 12

How can hoof support be provided to a laminitis case?

Answer 12

Aim - to stop pedal bone moving!

• Box rest
• Deep bedding
• FRog support

Question 13

What management changes can be done in a laminitic case?

Answer 13

• Box rest

- Diet - no grass, only poor quality hay, minimal concentrates or high fibre

Question 14

What is the prognosis of laminits?

Answer 14

Depends on clinical signs…

• Depression all round coronary band = 20%
• Previous attacks = 20%
• Rotations >11.5 = Slightly reduced
• Founder distance >15mm = 40% chance

Question 15

How do you prevent laminitis?

Answer 15

Avoid over consumption of CHO
Encourage growth of pasture
Diet changes
Treat any underlying disease

Question 16

What graxing changes should be made in a laminitis case?

Answer 16

Consider no grazing
Turn out late night to early morning
Restrict in spring and autumn
Avoid if frost or drought
REstrict intake
Rotate paddocks

Question 17

What supplements may be given to help prevent laminitis?

Answer 17

Cinnamon - insulin sensitising?
Magnesium - Modulates action of insulin
Chromium - potentiate action of insulin