Laminitis - diagnosis and treatment Flashcards

1
Q

How does laminitis progress in the feet (i.e. which ones are affected)

A

Both front feet
Then all four feet
Then both back feet only
Then one foot only ( rare but does occur)

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2
Q

How can the age of the horse help identify the cause of laminitis?

A

Less than 10yo = not PPID
10-15yo = maybe PPID
15yo or more = definitely consider PPID

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3
Q

What information needs to be gathered on the history of a horse with suspected laminitis?

A
  • 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)
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4
Q

Describe the initial assessment of a lame horse with suspected laminitis

A
  • 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
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5
Q

Describe the typical stance and gait features of a horse with laminitis

A
  • 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”
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6
Q

Describe the grades of laminitis using the Obel grading system

A

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

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7
Q

How should you examine the foot in suspected laminitis cases?

A
  • 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
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8
Q

List some differentials for laminitis

A
  • 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
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9
Q

When a horse has sore feet how can you determine if the horse has laminitis, or a bruised foot or an impending abscess?

A
  • 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
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10
Q

Name the 5 phases of laminitis

A

Prodromal phase
Acute phase
Stabilisation phase
Chronic phase
Soundness

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11
Q

Describe the prodromal phase of laminitis - what action can be taken?

A

Up to 72hrs before first signs are seen
Often unnoticed

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12
Q

Describe the acute phase of laminitis - what action can be taken?

A

Pain apparent
P3 may move
- Limit damage, analgesia, rest, support P3

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13
Q

Describe the stabilisation phase of laminitis - what action can be taken?

A

P3 stabilised in position. Still painful
Analgesia, rest, support P3, radiograph

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14
Q

Describe the chronic phase of laminitis - what action can be taken?

A

Pain lessening, new hoof growing
- Exercise? Analgesia? Trimming?

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15
Q

What are the aims of treating laminitis?

A

Remove the cause
Provide analgesia
Provide circulatory changing drugs
Support the foot
Investigate the cause
Rehabilitate the foot (trimming/shoeing)

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16
Q

How can you remove the cause of laminitis?

A

Treat endotoxaemia/colitis/ RFM etc.
Usually endocrinopathic so:-
- Remove from pasture
- Start dietary restriction
- Start on PPID treatment?

17
Q

Describe the analgesia given to laminitis cases

A
  • NSAIDs: phenylbutazone
  • Paracetamol (not licenced)
18
Q

Are nerve blocks used to treat laminitis? Explain.

A

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.

19
Q

Name two circulation changing drugs that can be used to treat laminitis

A

Acepromazine
Aspirin

20
Q

Describe the effects of acepromazine in treating laminitis

A

Vasodilation - Hypotension – reduce blood pressure to digit. Anxiolytic.
Probably only useful in acute stage

21
Q

Describe the effects of aspirin in treating laminitis

A

Not for analgesia – half life very short
Stabilizes platelets irreversibly
Not licensed

22
Q

Describe cryotherapy as a method of treating laminitis

A
  • 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
23
Q

What is the aim of supporting the foot to treat laminitis?

A

Aim to transfer weight to heels , frog and hoof wall, take weight off sole especially over tip of pedal bone.

24
Q

Should you remove the show in a laminitic horse?

A

May help weight distribution, but often very painful/hard work. Maybe best left alone in acute stages.

25
Q

How can you investigate if a horse has laminitis due to equine metabolic syndrome - what tests?

A
  1. Insulin measurement after oral glucose testing. Insulin effected by stress. Requires starved patient and glucose dosing.
  2. Adiponectin – cytokine which decreases in obesity and low levels linked to increasing laminitis risk and insulin sensitivity
  3. Instant diet
26
Q

Describe an instant diet for horses with suspected equine metabolic syndrome

A
  • Hay 1.5-2% of current body weight (dry weight) per 24 hours
  • Soak 8-16 hours
  • Balancer to provide protein, minerals, vitamins, to get drugs in etc.
  • No treats.
  • Means you need a weight tape and owners need a weight scales
27
Q

How can you investigate if a horse has laminitis due to PPID - what tests?

A

Blood sample for ACTH (EDTA),
Controversial if ACTH affected by stress/pain.

28
Q

Once the foot is stabilised what can you consider doing at this stage?

A

Trimming
- Radiographs useful

29
Q

What is the aim of trimming?

A

Designed to return foot to normal conformation – to “sculpt” it around the new position of the pedal bone
- Usually involves shortening the toe and removing excess heel
- Little and often best, horse maybe more painful after a trim (warn owners)

30
Q

Describe some more radical trimming techniques which may be carried out

A
  1. Dorsal wall resection – to relieve pressure under dorsal wall
  2. Coronary band grooving – relieve pressure on coronary band - not without risks
  3. Vertical grooving – allows rigid deformed hoof to expand and flex
31
Q

When can you start walking/ turnout/exercise following laminitis??

A

Not in the acute stage.
No hard and fast rules once foot stable but consider:-
- Level of pain
- Whether the animal is still on analgesia
- Weight management needs.
- Facilities ( pens/corrals etc.)
- Trend is to introduce some (gentle)exercise moving for chronic/stable cases.
- For return to work: must be completely sound and off analgesia

32
Q

Describe the prognosis of laminitis

A
  • Laminitis a common reason for euthanasia in equine practice
  • Not surprisingly the lighter the animal, the lower the condition score and the lower the Obel grade (milder cases) are more likely to survive.
  • Radiographs can also be used prognosticaly – a sinker distance >14mm – poor prognosis