Laminitis - diagnosis and treatment Flashcards
(32 cards)
How does laminitis progress in the feet (i.e. which ones are affected)
Both front feet
Then all four feet
Then both back feet only
Then one foot only ( rare but does occur)
How can the age of the horse help identify the cause of laminitis?
Less than 10yo = not PPID
10-15yo = maybe PPID
15yo or more = definitely consider PPID
What information needs to be gathered on the history of a horse with suspected laminitis?
- Age
- Has the animal had it before?
- How long has it been going on for this time? determine what stage of the disease we are in.
- Have you given any treatment yourself? it may already have been given bute (therefore maybe worse than it appears, or be at risk of bute toxicity)
Describe the initial assessment of a lame horse with suspected laminitis
- Is it a susceptible type?
- Condition score? obese? (NB: Most but not all EMS horses are overweight – regional adiposity important)
- Obviously cushingoid?
- Should be alert and responsive, willing to eat.
- HR and Resp rate maybe elevated due to pain, temp normal
- Cresty neck score
- Stance and gait
Describe the typical stance and gait features of a horse with laminitis
- Try to take weight off the affected feet
- Rocking back is the classical stance for a forelimb laminitis (moderate-severe)
- Reluctant to move
- Pottery, short steps
- Worse on hard or stony surfaces
- Exacerbated by turning
- ‘heel-toe’ foot impact
- Hind-limb laminitics: high stepping gait “cat on a hot tin roof”
Describe the grades of laminitis using the Obel grading system
1 - lameness is not evident at a walk but a short, stilted gait is noticed at trot
2 - stilted gait at a walk but moves willingly, a foot can be lifted off the ground without difficulty
3 - horse moves reluctantly and resists attempts to have the foot lifted
4 - horse refuses to move, doing so only if forced
How should you examine the foot in suspected laminitis cases?
- Assess all four feet
- Assess foot conformation
- Check for increased digital pulses: technically only a sign of hoof inflammation
- Palpate coronary band for evidence of sinking
- Heat in hoof: not reliable at all but beloved by owners
- Use hoof testers: squeeze and percuss foot. Most cases will have some generalised response to hoof tester but some horses have very thick rigid soles and it can difficult to get a response
List some differentials for laminitis
- Tetanus (stiff not painful, facial muscles affected)
- Colic vs Hindlimb laminitis: however laminitis cases will eat.
- Peritonitis/pleuropneumonia: maybe reluctant to move, ill, pyrexic, feet not painful.
- Grass sickness: abnormal stance but willing to move
When a horse has sore feet how can you determine if the horse has laminitis, or a bruised foot or an impending abscess?
- Can be very difficult to decide: especially if signs mild.
- Often only time will tell (Over next week - bruise improves, abscess gets worse, laminitis stays the same)
- Laminitics often bilateral with generalised foot pain on hoof testers
- Bruise/ abscess often unilateral with focal pain on hoof testers
Name the 5 phases of laminitis
Prodromal phase
Acute phase
Stabilisation phase
Chronic phase
Soundness
Describe the prodromal phase of laminitis - what action can be taken?
Up to 72hrs before first signs are seen
Often unnoticed
Describe the acute phase of laminitis - what action can be taken?
Pain apparent
P3 may move
- Limit damage, analgesia, rest, support P3
Describe the stabilisation phase of laminitis - what action can be taken?
P3 stabilised in position. Still painful
Analgesia, rest, support P3, radiograph
Describe the chronic phase of laminitis - what action can be taken?
Pain lessening, new hoof growing
- Exercise? Analgesia? Trimming?
What are the aims of treating laminitis?
Remove the cause
Provide analgesia
Provide circulatory changing drugs
Support the foot
Investigate the cause
Rehabilitate the foot (trimming/shoeing)
How can you remove the cause of laminitis?
Treat endotoxaemia/colitis/ RFM etc.
Usually endocrinopathic so:-
- Remove from pasture
- Start dietary restriction
- Start on PPID treatment?
Describe the analgesia given to laminitis cases
- NSAIDs: phenylbutazone
- Paracetamol (not licenced)
Are nerve blocks used to treat laminitis? Explain.
Nerve blocks will provide good analgesia but are contraindicated as a routine, regular treatment- the risk is the horse will move too much and displace the pedal bone further
They are however very helpful if you have to move a severely laminitic horse – to a stable, to an area for euthanasia area or for radiography.
Name two circulation changing drugs that can be used to treat laminitis
Acepromazine
Aspirin
Describe the effects of acepromazine in treating laminitis
Vasodilation - Hypotension – reduce blood pressure to digit. Anxiolytic.
Probably only useful in acute stage
Describe the effects of aspirin in treating laminitis
Not for analgesia – half life very short
Stabilizes platelets irreversibly
Not licensed
Describe cryotherapy as a method of treating laminitis
- Prevents carbohydrate overload laminitis if instigated before clinical signs seen
- Minimises damage in acute phase even if instigated after clinical signs seen
- Beneficial Vasoactive, analgesic, anti-inflammatory and hypometabolic effects
Effective – but very time consuming
What is the aim of supporting the foot to treat laminitis?
Aim to transfer weight to heels , frog and hoof wall, take weight off sole especially over tip of pedal bone.
Should you remove the show in a laminitic horse?
May help weight distribution, but often very painful/hard work. Maybe best left alone in acute stages.
