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Acute Laminitis inthe UKThe Redwings Study

Nicola Jarvis

BVetMed Cert AVP(EM) MRCVS

Redwings Horse Sanctuary

• Nine farms

• Over 1,300resident horses,ponies, donkeysand mules

• Over 500 more inguardian homes

• RSPCA, police,local councilrescue/welfarecases

Research?

• Sanctuary

• Limited projectsonly

• ‘Welfare is at theheart ofeverything we do’

• Laminitis is awelfare issue

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Study Proposal

• Comparison of Meloxicam against Phenylbutazone inthe treatment of acute laminitis in the horse (2007)

• Naturally occurring laminitis

• Boehringer Ingelheim Animal Health

• Royal Veterinary College, London

• Redwings Horse Sanctuary

Why do the study at all?

• Referring to laminitiscases resulting fromcolitis, carbohydrateoverload, colic –“providing they offercomparable pain relief,the selective COX2inhibitors may have theadvantage of sparing thegut barrier from furtherdamage”

• J Orsini et al (2009)

Why do the study at all?

• Phenylbutazone -only for equines ‘notintended for humanconsumption’

• Future legislation

• Metacam IVformulation 5ds

• Metacam oralformulation 3ds

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And will meloxicam work?

• “In this authorsexperience the moreCOX2 selective NSAIDs(fibrocoxib, meloxicam)are inferior to the non-COX selective NSAIDs foracute laminitis painalthough they may beeffective in chroniccases”

• Andrew W van Eps 2010

Inclusion Criteria• Minimum 24 months old

• Spontaneous laminitisoccurring at pasture

• Cases regardless of PPID,EMS or suspicion of such

• Recurrent cases onlyused if symptom andmedication free for 4weeks

• Assigned as either a‘new case’ or ‘recurrentcase’

• Horses and ponies!!

Exclusion Criteria

• Chronic lameness/OArequiring chronicNSAID therapy

• Medical disorderspredisposing tolaminitis, colic,metritis

• Animals withunknown recentmedical history

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Treatment protocol

• Immediately stabled

• Trailer if required

• Deep shaving bed

• Hay only diet

• Soaked high fibrepellets

• NSAID assigned

• ACP IV then oral BID

• Frog supports asrequired

NSAID assignment

Meloxicam - Metacam

• Day 0 – IV Metacam0.6mg/kg(3ml/100kg)

• Day 1 onwards –Metacam OralSuspension 0.6mg/kgmixed with handfulof high fibre/chaff

• Weight from weightape

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Phenylbutazone

• Day 0 – IV PBZ4.4mg/kg(2.2ml/100kg)

• Day 1-4 – PO PBZ2.2mg/kg BID

• Day 5 onwards – POPBZ 2.2mg/kg SID

• Weight from weightape

Cessation of treatment

• Study design 14 days• NSAID needed longer?

Metacam – 14 day licence• Duration of treatment – vet

guided• Remedial farriery (dorsal

wall resection etc) removedfrom trial

• Additional ‘rescue’ analgesiapermitted, no cross over ofmeloxicam andphenylbutazone.

• Not required

Evaluation of response totreatment

• Twice on day 0 – tocheck effect of IVNSAID

• Daily thereafter fornext 13 days

• Once at day 84 tocheck for recurrence

• Total treatment timerecorded

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Evaluation of response totreatment – OBEL score

• Grade 1 – At rest the animal alternatively lifts feet, no lamenessseen at walk, short stilted gait at trot on hard surface, turnscarefully at walk

• Grade 2 – Stiff gait at walk, does not move freely, short stiltedgait at trot, reluctant to trot on hard surface, turns with greatdifficulty, a foot can be lifted off the ground with relative ease

• Grade 3 – Reluctant to move on any surface, difficult to lift alimb, may be virtually non-weight bearing on one limb

• Grade 4 – Animal will not move without coercion, very reluctantto move from soft to hard ground, almost impossible to lift alimb, may be recumbent

• Obel, N (1948) Studies of the histopathology of acute laminitis

Clinician’s evaluation

• Overall response totreatment

• 0 – no response

• 1 – poor response

• 2 – good response

• 3 – excellentresponse

Composite Pain Index

• Glasgow composite pain score(Holton et al 1998) – dogs

• Modified version used inhorse with severe foot pain –laminitis and sub solarabscess – multimodalanalgesia (Dutton et al, EVE2009)

• Appetite, heart rate,respiratory rate, sweating,muscle fasciculation,recumbency – scored scale 0-10

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Composite Pain Index

• Rietmann, T.R. et al The association betweenheart rate, heart rate variability, endocrine andbehavioural pain measures in horses sufferingfrom laminitis. JVMA 2004; 51, 218-225

• Naturally occurring laminitis in 19 horses – PBZ,vedaprofen

• Mean heart rate decreased after NSAID – butlarge SDs

• HR and HRV affected by feeding, environment,movement and altered alertness

Composite Pain Index 0-12

• Relevant to study

• Horses not usuallystabled

• Ashley, F.H. et alBehavioural assessmentof pain in horses anddonkeys: application toclinical practice andfuture studies. EVJ2005;37(6), 565-575

Results

• Final number enrolled40 horses/ponies

• 30 ‘recurrent’ cases

• 10 ‘new’ cases

• Majority OBEL score 2

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Time course of OBEL grade - all cases

Time course of OBEL grade – new cases

Time course OBEL grade – recurrent cases

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Time course of OBEL grade – all cases

Pain score – recurrent cases

Sum Score Mean R1 or 2

0

0.5

1

1.5

2

2.5

0 0.5 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Days

Sco

res

Bute

Metacam

Pain score – new cases

Sum Score Mean N1 or 2

0

0.5

1

1.5

2

2.5

0 0.5 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Days

Sco

re Bute

Metacam

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Results

• Study suggestsmeloxicam hasequivalent efficacy toPBZ for thetreatment of acutelaminitis

Study critique

• Overall numbersenrolled sufficient

• ‘New cases’ – low studynumbers

• Assessor variability

• Primary clinicians‘aware’ of treatmentregime vs blinded

• Severity of cases –mainly OBEL 2

OBEL 3

• 4 horses OBEL 3

• None achieved OBELscore 0 by day 14

• PBZ final score OBEL3 and 1.5

• MLX final score OBEL1.5 and 0.5

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Future thoughts?

• Are there advantagesof COX2 specificdrugs in laminitiscaused by SIRS,colitis, post colicsurgery…..

Reasons To Work With Horses