Laminitis Flashcards
What is the most common cause of most laminitis cases?
Endocrinopathy
PPID, EMS
How can retained foetal membranes or other systemic infections lead to laminitis?
Laminitis is a consequence of SIRS/endotoxaemia
Hospitalised horses are at risk of developing supporting limb laminitis. What is this?
If non-weight bearing on one leg, develop laminitis on contra-lateral limb
What is glucocorticoid induced laminitis?
Laminitis due to high doses of glucocorticoid administration
(Esp in animals prone to laminitis)
How does carbohydrate overload cause laminitis?
Excess carbohydrates overwhelm intestines and cause bacterial proliferations
Release endotoxins which enter laminae
What is pastern associated laminitis?
Laminitis due to fructans intake (lush pasture)
What are the 3 components to EMS?
Obesity - predisposing factor
Insulin dysregulation/hyperinsulinaemia - pathogen
Laminitis - consequence
A consequence of laminar failure is that the hoof is free to move within the foot. What is capsular rotation? What is bony rotation?
Casular rotation - hoof diverges from dorsal surface of P3, but remains aligned with P2
Bony rotation - hoof capsule diverges from dorsal surface of P3 and P3 rotated palmarly around DIPJ (more severe - implies damage to DDFT)
What is a sinker?
Vertical displacement of P3 downwards
With or without rotation
Sinker horses are usually very painful and have a serious pathology. How does sinking affect the sole depth?
Thin soled
Prognosis may be hopeless if distance from extensor process on P3 to coronary band is >14mm
In the acute phase of pedal bone movement, what happens to the gap in the hoof?
Forms haematoma, seroma or necrotic tissue
can become foot abscess if infected!
What are some chronic consequences of pedal bone movement?
Haematoma forms lamellar wedge (dysplastic horn)
Pedal bone can become ‘Turkish slipper’
Abnormal hoof growth and shape
Compromised blood supply to coronary band
What age horses should you suspect PPID causing laminitis?
<10 = unlikely 10-15 = consider it >15 = definitely consider!
How are HR, RR and temperature affected by laminitis?
HR and RR may be higher due to pain
Temperature normal
How does cresty neck link t laminitis?
Horses with a cresty neck score above 3 likely to be hyperinsulinaemic
What feet are usually affected by laminitis if a horse has a high stepping gait, like a ‘cat on a hot tin roof’?
Hindlimbs
What are the 4 Obel grades of laminitis?
Grade 1 - lifting feet, shortened gait at trot
Grade 2 - horse has lameness at walk but moves willingly, can lift foot off ground without difficulty
Grade 3 - horse moves reluctantly and resists to have foot lifted
Grade 4 - horse refuses to move
How can you differ from laminitis or a bruised foot/abscess without radiographs?
Time will tell
Bruises improve
Abscesses get worse
Laminitis stays the same
What are the phases of laminitis?
Prodromal therapy Acute phase Stabilisation phase Chronic phase (most return to soundness )
What actions can be taken in the prodromal phase to reduce laminitis?
Cryotherapy
But often unnoticed
The first thing to do when treating laminitis is remove or treat the underlying cause. How can this be done to try limit endocrinopathies?
Take off pasture to monitor feed intake
restrict diet
Start on pergolide if PPID
A horse is laminitic and you suspect EMS. How can you confirm this? What are the disadvantages to this test?
Measure insulin after oral glucose
Requires starved patient, affected by stress
A horse is laminitic and you suspect PPID. How do you test for this?
Basal ACTH and LDDST
Tier 2 - TRH stimulation
If PPID is confirmed, what can be done with a horses diet to try prevent laminitis?
Soak hay overnight
Use balancer
Monitor weight with tape/scales
What pain relief can be given for 1st opinion laminitis cases?
Phenylbutazone
Paracetamol
Why should care be taken when giving PBZ daily for laminitis?
Can cause R dorsal colitis at high doses
esp ponies
Nerve blocks are contra-indicated as treatment for laminitis, however in some situations they may be used. Give an example. What nerve block should you use?
For euthanasia
For radiography
Abaxial sesamoid NB
What circulatory changing drugs can be used for laminitis management?
ACP - only in acute stages
Aspirin (no analgesia, not licensed)
How does ACP work to treat laminitis?
Causes vasodilation
Reduces blood pressure to laminae
Apart from diet changes, cryotherapy, circulatory medications and analgesia, what should be done to the foot to help with laminitis?
Trimming
Shoeing? Some cases
Lily pads for frog support
For a horse to return to work following laminitis, can they be on analgesia?
No - must be fully sound and off analgesia
What is a salvage procedure for laminitis when the DDFT pull is causing rotation or pain?
DDFT tenotomy
