Acute Laminitis in the UK The Redwings Study

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1 Acute Laminitis in the UK The Redwings Study Nicola Jarvis BVetMed Cert AVP(EM) MRCVS Redwings Horse Sanctuary Nine farms Over 1,300 resident horses, ponies, donkeys and mules Over 500 more in guardian homes RSPCA, police, local council rescue/welfare cases Research? Sanctuary Limited projects only Welfare is at the heart of everything we do Laminitis is a welfare issue 1

2 Study Proposal Comparison of Meloxicam against Phenylbutazone in the 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 laminitis cases resulting from colitis, carbohydrate overload, colic providing they offer comparable pain relief, the selective COX2 inhibitors may have the advantage of sparing the gut barrier from further damage J Orsini et al (2009) Why do the study at all? Phenylbutazone - only for equines not intended for human consumption Future legislation Metacam IV formulation 5ds Metacam oral formulation 3ds 2

3 And will meloxicam work? In this authors experience the more COX2 selective NSAIDs (fibrocoxib, meloxicam) are inferior to the non- COX selective NSAIDs for acute laminitis pain although they may be effective in chronic cases Andrew W van Eps 2010 Inclusion Criteria Minimum 24 months old Spontaneous laminitis occurring at pasture Cases regardless of PPID, EMS or suspicion of such Recurrent cases only used if symptom and medication free for 4 weeks Assigned as either a new case or recurrent case Horses and ponies!! Exclusion Criteria Chronic lameness/oa requiring chronic NSAID therapy Medical disorders predisposing to laminitis, colic, metritis Animals with unknown recent medical history 3

4 Treatment protocol Immediately stabled Trailer if required Deep shaving bed Hay only diet Soaked high fibre pellets NSAID assigned ACP IV then oral BID Frog supports as required NSAID assignment Meloxicam - Metacam Day 0 IV Metacam 0.6mg/kg (3ml/100kg) Day 1 onwards Metacam Oral Suspension 0.6mg/kg mixed with handful of high fibre/chaff Weight from weigh tape 4

5 Phenylbutazone Day 0 IV PBZ 4.4mg/kg (2.2ml/100kg) Day 1-4 PO PBZ 2.2mg/kg BID Day 5 onwards PO PBZ 2.2mg/kg SID Weight from weigh tape 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) removed from trial Additional rescue analgesia permitted, no cross over of meloxicam and phenylbutazone. Not required Evaluation of response to treatment Twice on day 0 to check effect of IV NSAID Daily thereafter for next 13 days Once at day 84 to check for recurrence Total treatment time recorded 5

6 Evaluation of response to treatment OBEL score Grade 1 At rest the animal alternatively lifts feet, no lameness seen at walk, short stilted gait at trot on hard surface, turns carefully at walk Grade 2 Stiff gait at walk, does not move freely, short stilted gait at trot, reluctant to trot on hard surface, turns with great difficulty, a foot can be lifted off the ground with relative ease Grade 3 Reluctant to move on any surface, difficult to lift a limb, may be virtually non-weight bearing on one limb Grade 4 Animal will not move without coercion, very reluctant to move from soft to hard ground, almost impossible to lift a limb, may be recumbent Obel, N (1948) Studies of the histopathology of acute laminitis Clinician s evaluation Overall response to treatment 0 no response 1 poor response 2 good response 3 excellent response Composite Pain Index Glasgow composite pain score (Holton et al 1998) dogs Modified version used in horse with severe foot pain laminitis and sub solar abscess multimodal analgesia (Dutton et al, EVE 2009) Appetite, heart rate, respiratory rate, sweating, muscle fasciculation, recumbency scored scale

7 Composite Pain Index Rietmann, T.R. et al The association between heart rate, heart rate variability, endocrine and behavioural pain measures in horses suffering from laminitis. JVMA 2004; 51, Naturally occurring laminitis in 19 horses PBZ, vedaprofen Mean heart rate decreased after NSAID but large SDs HR and HRV affected by feeding, environment, movement and altered alertness Composite Pain Index 0-12 Relevant to study Horses not usually stabled Ashley, F.H. et al Behavioural assessment of pain in horses and donkeys: application to clinical practice and future studies. EVJ 2005;37(6), Results Final number enrolled 40 horses/ponies 30 recurrent cases 10 new cases Majority OBEL score 2 7

8 Time course of OBEL grade - all cases Time course of OBEL grade new cases Time course OBEL grade recurrent cases 8

9 Time course of OBEL grade all cases Pain score recurrent cases Sum Score Mean R1 or Scores Bute Metacam Days Pain score new cases Sum Score Mean N1 or Score Bute Metacam Days 9

10 Results Study suggests meloxicam has equivalent efficacy to PBZ for the treatment of acute laminitis Study critique Overall numbers enrolled sufficient New cases low study numbers Assessor variability Primary clinicians aware of treatment regime vs blinded Severity of cases mainly OBEL 2 OBEL 3 4 horses OBEL 3 None achieved OBEL score 0 by day 14 PBZ final score OBEL 3 and 1.5 MLX final score OBEL 1.5 and

11 Future thoughts? Are there advantages of COX2 specific drugs in laminitis caused by SIRS, colitis, post colic surgery.. Reasons To Work With Horses 11