Laminitis - Causes + consequences Flashcards
1
Q
What is laminitis?
A
- Inflammation of the lamellae causing lameness
2
Q
Where does the horn grown from?
A
- From the coronary band
3
Q
What is the anatomy of the sole of the hoof?
A
- No lamellae on sole
- Weight bearing on lamellae, frog + walls of hoof - not sole
4
Q
What is the blood supply of the foot? (GLucose)
A
- V well vascularised - single hoof uses more glucose per day than its brain
- Glucose uptake not insulin mediated
- Glucose needed to keep basement membrane structures intact
5
Q
What are different theories of laminitis?
A
- Endotoxemic\sepsis\inflammatory theory
- Carbohydrate overload theory
- Supporting limb laminitis
- Mechanical laminitis
- Corticosteroid induced laminitis
- Endocrinopathic laminitis
6
Q
What is the theory of endotoxin causing laminitis?
A
- Laminitis recognised as complication of SIRS / endotoxaemia in horses
e.g. - RFM, colitis, post colic surgery, pleuropneumonia - Relevance = hospitalised horses
7
Q
What is the supporting limb laminitis?
A
- Horses non-weight bearing in one limb will often develop laminitis in the contralateral limb - due to failure of circulation + tissue ischaemia
- Relevance = hospitalised horses
8
Q
What is mechanical laminitis?
A
- Any force that tears hoof from laminae
- V traumatic one off or chronic forces on weakened digit
9
Q
What is glucocorticoid induced laminitis?
A
- Glucocorticoid administration can cause laminitis
- Relevance = owners should know there is a risk with corticosteroid use
10
Q
What is carbohydrate overload laminitis?
A
- Excessive carbs = overwhelms SI + overspills into large bowel = bacterial proliferation causes acidosis causing release of variety of laminitis inducing substances
11
Q
What sugars used by plants do horses struggle to digest leading to overspill to large bowel + causing bacterial proliferation + laminitis?
A
- Fructans - mammals lack enzymes to digest it = bacteria feast on the sugars
12
Q
What is endocrine induced laminitis?
A
- 90% of laminitis have underlying endocrinopathy =
-equine metabolic syndrome (EMS)
-pituitary pars intermedia dysfunction (PPID)
-EMS + PPID together - Changes of horse having laminitis if it doesn’t have EMS or PPID is low
13
Q
What is equine metabolic syndrome?
A
- Syndrome obesity, insulin dysregulation and laminitis.
- Thrifty” genotype leading to “survivor” phenotype enabling horses to survive in harsh conditions by putting on weight in good times to prepare for hard times.
- UK horses never experience “hard times” and so just get fatter and fatter…
- Lack of recognition of obesity in horse owners.
- Recent social trend to treat horses as “toys” causes welfare problems.
- Hyperinsulinaemia = cause of EMS related laminitis
14
Q
How does hyperinsulinaemia cause laminitis?
A
- Damages cytoskeleton of laminar cells and also has vasoactive properties
15
Q
How does PPID cause laminitis?
A
- Believed to be related it insulin dysregulation
- Older horses (>15y/o) - v common
