Scholarly article on topic 'Equine Cyathostominae Can Develop to Infective Third Stage Larvae on Straw Bedding'

Equine Cyathostominae Can Develop to Infective Third Stage Larvae on Straw Bedding Academic research paper on "Veterinary science"

0
0
Share paper
Academic journal
Equine Veterinary Journal
OECD Field of science
Keywords
{""}

Academic research paper on topic "Equine Cyathostominae Can Develop to Infective Third Stage Larvae on Straw Bedding"

CONTENTS

Clinical Research Abstracts

British Equine Veterinary Association Congress 2015 Volume 47 • Supplement 48 • September 2015

Foreword and Acknowledgements

Efficacy of oviductal flushing with PGE2, in mares, in and out of the breeding season

P. D. MARTYNSKI, R. J. PAYNE AND C. E. WYLIE

The effect of obesity and endocrine function on foal birthweight in Thoroughbred mares

S. SMITH, C. M. MARR AND N. J. MENZIES-GOW

Evaluation of several screening tests for determination of the IgG concentration of foals with the turbidimetric immunoassay as reference method

G. J. ZANDSTRA AND I. D. WIJNBERG

Antimicrobial sensitivity of bacteria isolated from neonatal foal samples in New Zealand (2004 to 2013)

L. J. TOOMBS-RUANE, C. B. RILEY, S. M. ROSANOWSKI, A. T. KENDALL, K. E. HILL AND J. BENSCHOP

Antimicrobial susceptibility of Australian virulent Rhodococcus equi isolates collected between 1991 and 2014

J. L. ALLEN, G. HERBERT, G. MUSCATELLO AND J. R. GILKERSON

Impact of age at first immunisation on equine influenza short and mid-term protective antibody levels in Thoroughbred foals

S. FOUGEROLLE, L. LEGRAND, M. FOURSIN, X. D'BLON, P. BAYSSAT, S. PRONOST AND R. PAILLOT

Colic: horse owner knowledge and experience

A. BOWDEN, M. L. BRENNAN, G. C. W. ENGLAND, J. H. BURFORD AND S. L. FREEMAN

Investigating the normal management regimens of working equids and identifying barriers to the recognition and treatment of colic by owners in Morocco

A. KALAMANOVA, A. P. STRINGER, S. L. FREEMAN AND J. H. BURFORD

Appraisal of the current evidence for diagnostic tests that differentiate medical and surgical colic

L. CURTIS, T. E. CULLEN, G. C. W. ENGLAND, J. H. BURFORD AND S. L. FREEMAN

Systematic review of evidence for plasma and peritoneal lactate as a diagnostic test for surgical colic

T. E. CULLEN, L. CURTIS, G. C. W. ENGLAND, J. H. BURFORD AND S. L. FREEMAN

Measures of redox balance in horses undergoing corrective surgery involving strangulating lesions of the small intestine

D. A. BARDELL, D. C. ARCHER AND P. I. MILNER

Evaluation of dexamethasone for the prevention of post operative ileus

K. F. McGOVERN, F. M. JAMES, H. D. O'NEILL AND B. M. BLADON

Is there evidence for functional 5-hydroxytryptamine 4 (5-HT4) receptors in the equine jejunum? An in vitro study to explore options for use of human prokinetic drugs, acting as 5-HT4 receptors, in horses

C. J. G. DELESALLE, C. CALLENS, I. van COLEN AND C. J. G. LEFEBVRE

Ethmoidal infection with Aspergillus spp. in 3 horses: successful treatment by transendoscopic removal of mycotic plaques alone or in combination with systemic itraconazole

M. J. P. THEELEN, E. W. SIEGERS AND J. M. ENSINK

Iohexol as a marker of intestinal permeability in the horse

M. J. KOSKINEN, M. HEWETSON AND M. R. POYTAKANGAS

Diagnostic accuracy of blood sucrose as a screening test for diagnosis of gastric ulceration in adult Horses

M. HEWETSON, B. W. SYKES, G. HALLOWELL AND R. M. TULAMO

Diagnostic value of gastric mucosal biopsies in horses with glandular disease

S. M. CRUMPTON, K. BAIKER, G. D. HALLOWELL, J. L. HABERSHON-BUTCHER AND I. M. BOWEN

Understanding intestinal microbiota in equine grass sickness: next generation sequencing of faecal bacterial DNA

J. LENG, C. PROUDMAN, F. BLOW, A. DARBY AND J. SWANN

Equine cyathostominae can develop to infective third stage larvae on straw bedding

E. C. McGIRR, M. J. DENWOOD, J. McGOLDRICK AND S. LOVE

A retrospective dental study on 5334 horses in general practice

G. DUNCANSON

Head and pelvic movement asymmetries at trot in riding horses perceived as sound by their owner

M. RHODIN, A. EGENVALL, P. H. ANDERSEN AND T. PFAU

Objective assessment of back kinematics and movement asymmetry in horses: effect of elastic resistance band training

V. SIMONS, R. WELLER, N. C. STUBBS, N. ROMBACH AND T. PFAU

Thoracolumbar movement in sound horses trotting in hand and on the lunge

L. GREVE, S. DYSON AND T. PFAU

An in vitro investigation of the effect of curve running on equine distal limb tendon strain

R. S. V. PARKES, T. H. WITTE, T. PFAU AND R. WELLER

Goniometric measurement of limb stiffness: validation of a potential predictor of tendon healing

R. TUCKER, B. D. JACKLIN, S. GILLESPIE, L. VAUGHAN, A. R. FISKE-JACKSON AND R. K. SMITH

What effect does medium and extended trot have on the kinematics of the forelimb in dressage horses?

V. A. WALKER, C. A. TRANQUILLE, S. J. DYSON, R. NEWTON AND R. C. MURRAY

Identification of disease specific metabolic fingerprints in early osteoarthritis

M. PEFFERS, C. RIGGS, M. PHELAN AND P. CLEGG

Normal radiographic anatomy of the donkey foot from birth to 2 years of age

B. van THIELEN, P. PESTIEAU, A. van der STRIECKT, I. WILLEKENS, V. BUSONI, F. VERHELLE, P. GOOSSENS, P. DELPERDANGE, G. de MOL, O. JACQMOT, N. BULS, M. KICHOU AND J. de MEY

Effects of time of day, ambient temperature and relative humidity on the repeatability of infrared thermographic imaging in horses

G. SATCHELL, M. McGRATH, J. DIXON, T. PFAU AND R. WELLER

Sensitivity of transcranial magnetic stimulation in relation to histopathological findings in six horses with compressive lesions of the spinal cord

K. VANSCHANDEVIJL, H. NOLLET, G. VERCAUTEREN, R. DUCATELLE AND P. DEPREZ

Diffusion of radiodense contrast medium after perineural injection of the palmar digital nerves

A. NAGY AND R. MALTON

Diffusion of radiodense contrast medium after a mid-pastern ring block

R. MALTON AND A. NAGY

Proximal suspensory desmopathy in hindlimbs: a correlative clinical, ultrasonographic, gross post mortem and histological study

S. DYSON AND M. J. PINILLA

An epidemiological investigation of the aid of magnetic resonance imaging in determining long-term prognosis for soundness following palmar/plantar digital neurectomy for chronic foot pain

C. E. WYLIE, R. J. PAYNE, A. P. BATHE, T. R. C. GREET, M. J. HEAD, S. J. BOYS-SMITH AND S. E. POWELL

The use of electromyography including interference pattern analysis to determine muscle force of the deep digital flexor muscle in case of equine laminitis

L. C. HARDEMAN, B. R. van der MEIJ, W. BACK, J. H. van der KOLK AND I. D. WIJNBERG

A retrospective study of sagittal plane slab fractures of the third carpal bone in racing Thoroughbred horses

R. E. TALLON AND B. M. BLADON

Plant thorn synovitis caused by Prunus spinosa (blackthorn) penetration in 35 horses

N. M. ASHTON AND J. DOLES

The effect of three different shoeing conditions on tendon strain in the Thoroughbred forelimb

B. AULT, G. STARLING, R. PARKES, T. PFAU, C. PARDOE, P. DAY, C. BETTISON AND R. WELLER

Outcome and owner perception of conservative and surgical management of fracture of the ulna in 20 horses

S. LADEFOGED, J. WALLIN, T. TOTH AND P. H. ANDERSEN

A preliminary study of the effect of manual chiropractic treatment on the splenius muscle in horses when measured by surface electromyography

J. LANGSTONE, J. ELLIS AND C. CUNLIFFE

A comparison of a 4% modified fluid gelatin and a 6% hydroxyethyl starch on haemodilution, colloid osmotic pressure, haemostasis and renal parameters in healthy ponies

Z. GRATWICK, A. VILJOEN, P. C. PAGE, A. GODDARD, G. T. FOSGATE AND C. H. LYLE

Yellow fat disease (steatitis): description of 20 cases with emphasis on typical ultrasonographic findings

G. van LOON, L. LEFERE, C. BAUWENS, K. KLEYN, B. BROUX, D. de CLERCQ AND P. DEPREZ

Accuracy and complication rates of maxillary nerve blocks: a comparison of techniques using surface landmarks, ultrasound and GPS-guidance

B. CORDNER, J. DIXON AND T. WITTE

Antimicrobial resistance of aerobic respiratory isolates from young New Zealand horses

L. J. TOOMBS-RUANE, C. B. RILEY, S. M. ROSANOWSKI, A. T. KENDALL AND J. BENSCHOP

Development and evaluation of a molecular diagnostic method to rapidly detect Histoplasma capsulatum var. farciminosum (causing epizootic lymphangitis) from equine clinical samples

C. E. SCANTLEBURY, G. L. PINCHBECK, P. LOUGHNANE, T. ASHINE, N. AKLILU, A. P. STRINGER, L. GORDON, R. M. CHRISTLEY AND A. J. McCARTHY

21 A neglected and emerging helminthosis: a case of equine fasciolosis

M. A. GETACHEW, G. INNOCENT, S. W. J. REID, F. BURDEN AND S. LOVE

21 Factors affecting complication rates with subpalpebral lavage catheter use in horses

S. CORNELISSEN, E. FINDING, I. M. BOWEN, C. BULLARD AND G. D. HALLOWELL

22 Detection of the toxin hypoglycin a in pastured horses and in the European sycamore maple tree (Acer pseudoplatanus) during two outbreaks of atypical myopathy in Sweden

G. GRONDAHL, A. BERGLUND, J. SKIDELL, U. BONDESSON AND M. SALOMONSSON

22 Longitudinal observations of silent carriers of Streptococcus equi in a Swedish yard

G. GRONDAHL, V. BAVERUD, H. LJUNG, V. MELYS, A. ASPÁN AND M. RIIHIMAKI

22 Expression of insulin-related genes and release of non-essential fatty acids NEFA from neck crest fat compared to abdominal, mesenteric, and tail pad fat in horses

M. G. BERNHARDSSON AND L. C. BERG

23 Thyroid hormone and thyrotropin concentrations and responses to thyrotropin releasing hormone in ageing horses

B. A. BREUHAUS

23 Basal insulin and insulin dysregulation in obese and non-obese Andalusian horses with and without cresty neck

T. MARTIN GIMÉNEZ, C. N. AGUIRRE PASCASIO AND I. de BLAS GIRAL

24 Triamcinolone administration does not increase overall risk of developing laminitis

E. HAMMERSLEY, M. DUZ AND J. F. MARSHALL

24 Informed hypothetico-deductive reasoning based on clinical signs for diagnosis of equine laminitis using decision tree analysis

C. E. WYLIE, D. J. SHAW, K. L. P. VERHEYEN AND J. R. NEWTON

25 An anatomical study of the dorsal and ventral nasal conchal bullae in normal horses: gross morphology and histological features

T. J. FROYDENLUND, P. M. DIXON, S. H. SMITH AND R. J. M. REARDON

25 Prevalence of and risk factors for recurrent airway obstruction in geriatric horses and ponies

J. L. IRELAND, R. M. CHRISTLEY, C. M. McGOWAN, P. D. CLEGG AND G. L. PINCHBECK

26 Do BALF cytokine profiles vary depending on the sampled lung in horses with unilateral IAD-consistent cytology?

E. HUE, M. ORARD, M. DEPECKER, A. COUROUCÉ-MALBLANC, R. PAILLOT, S. PRONOST AND E. A. RICHARD

26 Comparison of nanoparticulate CpG immunotherapy with and without allergens in RAO-affected horses

J. KLIER, S. GEIS, J. STEUER, S. REESE, S. FUCHS, R. S. MUELLER, G. WINTER AND H. GEHLEN

26 Ultrasonographic identification of the pulmonary veins in adult horses

G. van LOON, T. VANDECASTEELE, K. VANDEVELDE, A. DECLOEDT, D. de CLERCQ AND P. CORNILLIE

27 Causes of pleural effusion in horses in the UK

I. JOHNS AND T. McPARLAND. Presented by T. MAIR

27 Post exercise cardiac troponin I release and clearance in normal Standardbred racehorses

T. M. ROSSI, D. L. PEARL, W. G. PYLE, M. G. MAXIE, P. A. KAVSAK AND P. W. PHYSICK-SHEARD

28 Retrospective observational study on the outcome of medical treatment of atrial fibrillation

R. J. LOTSTRA, J. van den BROEK, T. POWER, C. M. MARR AND I. D. WIJNBERG

Equine Veterinary Journal

Equine Veterinary Journal ISSN 0425-1644 DOI: 10.1111/evj.12486

Clinical Research Abstracts

British Equine Veterinary Association Congress 2015

Foreword and Acknowledgements

This supplement is devoted to the publication of abstracts from the 2015 Congress of The British Equine Veterinary Association. The quality of research at the Congress was, as in previous years, high, and the selection process was difficult. Despite the inclusion of a larger number of research communications than in previous years only two-thirds of those submitted could be accepted. This year's Congress committee utilised the selection process initiated last year by Professor Celia Marr in partnership with EVJ. Abstracts were reviewed and objectively graded by two peer reviewers and a member of the Congress Committee before being subjected to a final selection process overseen by the Congress Chair. Thereafter, abstracts had to satisfy the requirements of EVJ for publication in this supplement. Those authors who have had their work accepted should be proud of their achievement. Those who were unsuccessful are doubtless disappointed; however, they have the reassurance that the standard was high and the process was fair.

Implementing such a process necessitates a considerable amount of work by dozens of individuals. I am extremely grateful to Professor Celia Marr, Sue Wright and Jane Woodley at EVJ for inviting the Congress Committee to work in partnership with them and for enabling us to utilise their review process. Without the infrastructure provided by EVJ, such a comprehensive review process would not have been possible, and without the endless patience and assistance of the aforementioned individuals, it could not have worked. The Congress Committee themselves: Debbie Archer, Madeleine Campbell, Huw Griffiths, Philip Ivens, Andy Fiske-Jackson, Malcolm Morley, Michael Schramme, Henry Tremaine and Lesley Young deserve thanks and recognition for a year of hard work. Particular thanks also to all of the anonymous peer reviewers who receive no recognition but gave their time not only to grade the abstracts submitted but also to provide constructive feedback to their authors.

The selection process adopted for BEVA Congress sets a standard for other meetings to follow. Given the increasing competition for acceptance of research communications at major international meetings, and the importance of achieving acceptance for those seeking to fulfil the requirements of specialist colleges, such a rigourous selection process seems only right.

David Rendle

Chairman BEVA 2015 Scientific Programme Guardians

Congress Session Sponsors

Animal Health

Rainbow^

Equine Hospital

UNIVERSITY OF

LIVERPOOL

EFFICACY OF OVIDUCTAL FLUSHING WITH PGE2, IN MARES, IN AND OUT OF THE BREEDING SEASON

Martynski, P.D., Payne, R.J. and Wylie, C.E.

Rossdales Equine Hospital & Diagnostic Centre, Cotton End Road, Exning, Newmarket, Suffolk, CB8 7NN, UK. Email: pmartynski@rvc.ac.uk

Reasons for performing study: There are limited data surrounding the efficacy of oviductal flushing in restoring fertility in mares with repeated returns to oestrus.

Objectives: To determine the conception and foaling rates in mares treated by laparoscopic topical application of prostaglandin E2 (PGE2) to the oviduct(s) in mares: i) in the breeding season (January-May), pre-covering; ii) in the breeding season, post covering; and iii) out of the breeding season (June-December).

Study design: Follow-up study.

Methods: Analysis of electronic patient records (EPRs) identified 29 mares that underwent oviductal flushing via laparoscopic surgery between 1 January 2008 and 12 October 2014. One mare underwent the procedure twice; once in the breeding season (pre-covering) and once out of the breeding season. Follow-up data were collected via EPRs and from Weatherbys (www.bloodstockreports.co.uk).

Results: The procedure was used in 27 Thoroughbreds, one Warmblood and one Hanoverian. Mean age at the time of the procedure was 13.1 years (range 6-22 years). Mean duration barren prior to the procedure was 1.9 years (range 49 days-5.6 years). The mean time post flushing to the first positive ultrasound scan was 31 days, with average time post flushing to foaling of 367.6 days. Of the 29 horses, 55.2% (16/29) conceived successfully, with 87.5% of these confirmed to have produced a live foal. In the breeding season, 16 mares were treated; 10 pre-covering, and 6 post covering with conception rates of 60.0% and 83.3%, respectively. Thirteen mares were treated out of the breeding season, with a 35.7% conception rate.

Conclusions: Oviductal flushing within the breeding season was more successful in this study than flushing performed out of the breeding season. Restoration of fertility in this study was lower than that previously reported and potential reasons for this include limited pre-surgical diagnostic testing, differing prior pathologies or reasons for sub-fertility, and case selection.

Ethical animal research: Research ethics committee oversight not currently required by this conference: retrospective study of clinical records. Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: C.E. Wylie is funded by the Margaret Giffen Trust. Competing interests: None declared.

THE EFFECT OF OBESITY AND ENDOCRINE FUNCTION ON FOAL BIRTHWEIGHT IN THOROUGHBRED MARES

fSmith, S., *Marr, C.M. and fMenzies-Gow, N.J.

fRoyal Veterinary College, London; *Rossdales Equine Hospital, Exning,

Newmarket, UK.

Email: sasmith@rvc.ac.uk

Reasons for performing study: The birthweight of Thoroughbred foals has increased in recent years. It is unknown whetherthis is associated with increased broodmare obesity or endocrine dysfunction.

Objectives: To determine insulin, leptin and triglyceride concentrations in obese and non-obese Thoroughbred mares throughout gestation and to investigate their association with foal birthweight.

Methods: Fifty-seven pregnant Thoroughbred mares were included in the study. From 40 days post-breeding, body condition score (BCS), weight and venous blood samples were obtained every 60 days throughout gestation. Feed was withheld for6 h before blood sampling. Serum/plasma insulin, leptin and triglyceride concentrations were measured using validated/standard methods. Foal birthweight was recorded. Association of hormone or triglyceride concentration with time, BCS and birth-weight were analysed using a linear mixed effects model. A Pearson correlation co-efficient was calculated between hormone or triglyceride concentration, BCS and birthweight.

Results: Serum insulin concentrations were significantly greater (P<0.05) at 0-59 days compared with 240-299 days and at 60-119 days compared with 180-359 days gestation. 55% of mares had BCS > 7. There was 1.5% incidence of fasting hyperinsulinaemia throughout gestation and no association of fasting insulin concentration with BCS. Leptin concentration was significantly (P<0.0001) greater at 180-239 days compared with all othertime points and was significantly (r = 0.29, P<0.0003) correlated with BCS. Triglyceride concentration was significantly (P<0.02) greater at 240-299 days compared with earlier time points but was not associated with BCS. Foal birthweight was significantly positively correlated with BCS (r = 0.13, P<0.001) and inversely correlated with leptin concentration at 60-119 days and 240-299 days gestation (r = -0.64, P<0.05).

Conclusions: Mare BCS correlated with foal birthweight such that obese mares had heavier foals. Significant fasting hyperinsulinaemia was not identified in this population. Increased leptin concentration in early and late gestation was associated with decreased foal birthweight and may be useful to predict foal birthweight.

Ethical animal research: Informed client consent was obtained for all animals used in the study. Source of funding: Private donor. Competing interests: None declared.

EVALUATION OF SEVERAL SCREENING TESTS FOR DETERMINATION OF THE IgG CONCENTRATION OF FOALS WITH THE TURBIDIMETRIC IMMUNOASSAY AS REFERENCE METHOD

Zandstra, G.J. and Wijnberg, I.D.

Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 112-114,3584 CM Utrecht, The Netherlands. Email: i.d.wijnberg@uu.nl

Reasons for performing study: The measurement of immunoglobulins is important in foals, as individuals with evidence of failure of passive transfer are at increased risk of infection and death during the first month of life.

Objectives: To identify which test is most suitable for determining the foal's IgG concentration as applied in practice. A distinction was made between hospitalised foals and healthy low risk foals in the field.

Study design: Prospective study including 46 foals <7 days old, divided into 4 groups based on age and health status. Sensitivity and specificity were calculated manually. Significance was set at P<0.05.

Methods: Several screening tests were compared to the IgG concentration measured by turbidimetric immunoassay: serum and plasma total protein, albumin and protein spectrum including gamma globulin concentration (GGC) measured by chemistry analyser, total protein by refractometer, glutaraldehyde coagulation test and a semi-quantitative enzyme immunoassay (SNAP). IBM SPSS Statistics 20A was used. A one-way ANOVA with a 95% confidence interval (CI) was used for determining significant differences among tests and between groups.

Correlations between the turbidimetric immunoassay and the screening tests were calculated using linear regression with a 95% CI.

Results: Group differences were not found. The most accurate alternative test was the combination of total serum protein measured by a chemistry analyser (R 0.83) and GGC (R0.84) with sensitivity and specificity of 79 and 100% and 95 and 93% respectively. A total serum protein of >49 g/l and a GGC of >6 g/l corresponded with an IgG concentration of >8 g/l.

Conclusions: According to this study, the most reliable alternative test suitable in a clinical setting forthe determination of IgG concentration was measuring total serum protein by a chemistry analyser in combination with serum GGC.

Ethical animal research: The research was approved by the Animal Welfare Committee of Utrecht University (approval number 2012.II.05.078). Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: None. Competing interests: None declared.

ANTIMICROBIAL SENSITIVITY OF BACTERIA ISOLATED FROM NEONATAL FOAL SAMPLES IN NEW ZEALAND (2004 TO 2013)

+Toombs-Ruane, L.J., +Riley, C.B., +*Rosanowski, S.M., t§Kendall, A.T., +Hill, K.E. and +Benschop, J.

fInstitute of Veterinary and Biomedical Sciences, Massey University, Palmerston North 4442, New Zealand; *Royal Veterinary College, University of London, London, NW1 0TU, UK; sMalaren Equine Clinic, Sigtuna, Sweden.

Email: l.j.toombs-ruane@massey.ac.nz

Reasons for performing study: Guidelines for the rational use of antimicrobials enable practitioners to improve antimicrobial stewardship and slow the development of antimicrobial resistance (AMR) [1]; these must be regionally relevant [2]. New Zealand (NZ) is geographically isolated and the importance of AMR on equine studs is unknown.

Objectives: To identify AMR patterns of bacteria isolated from NZ foals so as to provide regionally specific information for the development of antimicrobial stewardship guidelines.

Study design: Retrospective study of clinical pathology records.

Methods: A database search of bacterial culture submissions from foals <3 weeks of age from April 2004 to December 2013 was completed. Culture results, antimicrobial sensitivities, and demographic factors were tabulated. The Kirby-Bauer disk diffusion susceptibility test was used to define sensitivity. Multi-drug resistance (MDR) was defined as non-sensitivity to 3 or more core antimicrobials in a panel (ceftiofur, enrofloxaxin, gentamicin, penicillin [not included for Gram-negative bacteria], tetracycline, trimethoprim- sulfamethoxazole).

Results: Bacterial isolates (n = 127) were cultured from 64/102 (62.7%) of foal submissions. Four bacterial groups (Staphylococcus spp., Streptococcus spp., Enterococcus spp. and Escherichia coli) accounted for 100 (79%) of bacterial isolates cultured. At least one or 2 MDR isolates were cultured from 24 (38%) and 8 (12%) foals, respectively. Culture positive and negative foals were demographically similar.

Conclusions: A significant number of bacterial isolates from foals have reduced antimicrobial susceptibility to commonly used antimicrobial drugs. The results are of concern from treatment and stewardship perspectives. Multi-drug resistance was found, indicating a need for regionally relevant antimicrobial use recommendations.

Ethical animal research: Not applicable. Sources of funding: Massey University McGeorge fund; New Zealand Equine Research Foundation. Competing interests: None declared.

1. Prescott, J.F. (2014) The resistance tsunami, antimicrobial stewardship, and the golden age of microbiology. Vet. Microbiol. 171, 273-278.

2. Morley, P.S., Apley, M.D., Besser, T.E., Burney, D.P., Fedorka-Cray, P.J., Papich, M.G., Traub-Dargatz, J.L. and Weese, J.S., American College of Veterinary Internal Medicine (2005) Antimicrobial drug use in veterinary medicine. J. Vet. Intern. Med. 19,617-629.

ANTIMICROBIAL SUSCEPTIBILITY OF AUSTRALIAN VIRULENT RHODOCOCCUS EQUI ISOLATES COLLECTED BETWEEN 1991 AND 2014

+Allen, J.L., +Herbert, G., *Muscatello, G. and +Gilkerson, J.R. fCentre for Equine Infectious Disease, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia; ^Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Australia. Email: jrgilk@unimelb.edu.au

Reasons for performing study: Bronchopneumonia caused by Rhodococcus equi is an important disease of young horses throughout the world. Although early diagnosis and treatment improves the prognosis, this also increases the amount of antimicrobial usage and therefore increases the likelihood of resistance developing.

Objectives: The aim of this study was to determine the level of resistance to commonly prescribed antimicrobial agents of 97 virulent Rhodococcus equi isolates.

Study design: Analysis of archived samples.

Methods: Virulent Rhodococcus equi isolates were collected between 1991 and 2014 from clinically affected horses and from air samples collected in the breathing zone of foals. Antimicrobial susceptibility of these isolates was assessed using a disc diffusion assay with a panel of agents. The minimum inhibitory concentration (MIC) was determined for rifampicin, erythromycin, tetracycline, and neomycin using a novel resazurin-based microtitre assay.

Results: Resistance to rifampicin was detected in 3 of the isolates (2 collected in 2013 and one in 2014) by both methods. The MIC for these isolates was 64 |g/ml (n = 2) and 16 |g/ml (n = 1). All isolates collected prior to 2013 had MICs<0.125 |g/ml, which was the limit of detection in this assay. Although no isolates were resistant to tetracycline, there was a general increase in MIC in isolates collected in recent years. No isolates were resistant to either neomycin or erythromycin, with MIC values ranging between 0.25 and 2 |g/ml for neomycin and 0.125-1 |g/ml for erythromycin.

Conclusions: The success of the macrolide-rifampicin combination relies on the synergistic action of these 2 agents. Resistance to rifampicin will reduce the therapeutic efficacy of this treatment. It is of serious concern that the resistant isolates were all recently collected. Hopefully, recent research will lead to fewer asymptomatic foals receiving antimicrobials which will in turn reduce the likelihood of ongoing development of resistance.

Ethical animal research: All organisms in this study were received by the laboratory from diagnostic accessions. Sources of funding: Funding for the study was provided by Rural Industries Research and Development Corporation and the University of Melbourne. G. Herbert was the recipient of a RN McCarthy scholarship from the Faculty of Veterinary Science. Competing interests: None declared.

IMPACT OF AGE AT FIRST IMMUNISATION ON EQUINE INFLUENZA SHORT AND MID-TERM PROTECTIVE ANTIBODY LEVELS IN THOROUGHBRED FOALS

t*5'Fougerolle, S., tt5#Legrand, L., "Foursin, M., «D'Ablon, X., §§Bayssat, P., t*§*1Pronost, S. and *§**,1Paillot, R.

tFrankDuncombeLaboratory-LABÉO, 1 route de Rosel, 14053 Caen Cedex 4, France; *Normandie Université, 14000 Caen, France; §Unité Risques Microbiens (U2RM), EA 4655, 14032 Caen, France; #Hippolia Foundation, La Maison du cheval, 6 avenue du Maréchal Montgomery, 14000 Caen, France; ffClinique Equine de la Boisrie, La Boisrie, 61500 Chailloué, France; **Clinique Vétérinaire de la Côte Fleurie, Route de Paris - Bonneville sur Touques, 14800 Deauville, France; §§Clinique Vétérinaire de Bayeux, Route de la Cambette, 14400 Bayeux, France; ##Animal Health Trust, Centre for Preventive Medicine, Lanwades Park, Kentford, Newmarket, CB8 7UU, UK. Email: stephanie.fougreolle@calvados.fr 1These authors contributed equally.

Reasons for performing study: Every year, several equine influenza (EI) epidemics are reported worldwide. Equine influenza vaccination is the most efficient method of prevention; however, not all horses develop sufficient immunity after EI immunisation, increasing the risk of infection, infectious virus excretion and the spread of the disease.

Objectives: This study aimed to better understand poor vaccine response mechanisms during the primary EI vaccination.

Study design: Cohort study.

Methods: The EI humoral immune response was measured in 118 Thoroughbred foals set in 3 different stud farms (SF#1 to SF#3) after the primary course of EI vaccination. All foals were immunised with a recombinant canarypox-based EI vaccine, following the vaccine manufacturer's recommendations. The age at first vaccination was 4 to 8 months. Sera were tested by single radial haemolysis (SRH) against the A/equine/Jouars/4/2006 EIV strain (Florida clade 2) at the time of the first vaccination (V1), 2 weeks and 3 months after the second immunisation (V2), 2 days and 3 months after the third immunisation (V3).

Results: Short (V2 + 2 weeks) and mid-term (V3 + 3 months) SRH antibody levels were statistically different between the stud farms (P-value = 0.0011 and 0.003, respectively), with SF#1<SF#3<SF#2 and SF#1 SRH antibody titres below the protection threshold (i.e. 85 mm2) atall time points studied. SRH antibody levels induced by EI vaccination were related to the age of foals at the first immunisation (SF#1 median age 143 days, SF#2 median age 181 days and SF#3 median age 156 days), but were independent of the presence of maternal derived antibodies (MDA; P-value 0.41). Given the results in SF#1, a booster immunisation (V4) was brought forward to restore protective levels of antibody.

Conclusion: Independently of the presence of MDA, the age of foals at first immunisation plays an important role in the establishment of adequate antibody levels.

Ethical animal research: All animal work received ethical approval, and consent was obtained from the owners. Sources of funding: This study was supported by the Basse-Normandie Region council (France) and the European Regional Development Fund. Competing interests: None declared.

COLIC: HORSE OWNER KNOWLEDGE AND EXPERIENCE

Bowden, A., Brennan, M.L., England, G.C.W., Burford, J.H. and Freeman, S.L.

School of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, Loughborough, Leicestershire, LE12 5RD, UK.

Email: svxab4@exmail.nottingham.ac.uk

Reasons for performing study: Colic is the most common equine emergency problem, and one of the main causes of equid deaths. The horse owners' ability to recognise colic is a critical first step in determining case outcome.

Objectives: To assess equine owners' knowledge and recognition of colic.

Study design: Online questionnaire of horse owners.

Methods: An online survey was designed to evaluate owners' approach to colic in the horse. The survey included questions on owner demographics, their recognition of colic (including owner's opinions of their ability to recognise colic, their approach, and their recognition of colic using case vignettes), and their knowledge of normal ranges for clinical parameters. Descriptive and chi squared statistical analysis was performed.

Results: The survey was completed by 1061 UK respondents. Sixpercent of owners thought they could recognise all types of colic, 61% said they could recognise most cases and 30% said they could recognise some but not all cases. Owners said they would assess faecal output (73% of respondents), gastrointestinal sounds (69%), respiratory rate (62%) and heart rate (50%) in horses with suspected colic. One fifth (22%) of owners would call a vet immediately without assessing any parameters. Many respondents either did not know, or provided incorrect estimates of normal values for clinical parameters: 30.4% were 'unsure' of the normal heart rate and 35.5% gave heart rate values which were outside reference ranges; only 24.5% gave appropriate values for normal respiratory rates and only 31% gave normal temperature values. There was no statistical significance between participants' age, educational qualifications, or their experience with horses and their knowledge of normal clinical parameters.

Conclusions: Owners varied in their approach and ability to recognise colic, and many had significant gaps in their knowledge of normal parameters. Educational materials and/or training to assist owners could help address these issues.

Ethical animal research: The study did not involve animal research. The study was reviewed and approved by the Ethics Committee, School of Veterinary Medicine and Science, University of Nottingham. The questionnaire was conducted in accordance with the 1998 Data Protection Act, and the British Educational Research Association's Revised Ethical Guidelines for Educational Research (2004). Source of funding: Adelle Bowden's studentship is funded by the School of Veterinary Medicine and Science, University of Nottingham. Competing interests: None declared.

INVESTIGATING THE NORMAL MANAGEMENT REGIMENS OF WORKING EQUIDS AND IDENTIFYING BARRIERS TO THE RECOGNITION AND TREATMENT OF COLIC BY OWNERS IN MOROCCO

tKalamanova, A., ^Stringer, A.P., freeman, S.L. and burford, J.H. fSchool of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, Loughborough, Leicestershire, LE12 5RD, UK; *One Health Consulting, 32 Gladstone Road, Neston, CH64 9PJ, UK.

Email: svyak3@nottingham.ac.uk

Reasons for performing study: Colic is a common reason for owners to seek veterinary treatmentfortheirworking equids in Morocco. There is no information available regarding cultural, religious or educational barriers to obtaining treatment or about the typical workload of these animals which may predispose them to colic.

Objectives: To characterise the typical workload and feeding regimens of working equids in Morocco; to characterise the ability of owners to recognise the clinical signs and causes of colic; and to identify specific barriers to the veterinary treatment of colic.

Study design: Questionnaire-based survey.

Methods: A standardised, structured questionnaire was administered, with the assistance of an Arabic speaking interpreter, to the owners of working equids presenting their animals to 2 centres run by SPANA (The Society for the Protection of Animals Abroad). Participation was voluntary and informed consent was obtained prior to the interview.

Results: All of the 102 participants that completed questionnaire were male. Ninety-eight owners used their animals for pulling carts, with 12% of animals working 7 days per week. 14% of animals were offered water by their owner once per day and 2% every other day. 25% of animals were loose and allowed free to feed unsupervised when not working. 29% of owners were not able to name any cause of colic and 25% did not recognise any clinical signs; only 12% associated colic with gastrointestinal pain. 83% of owners would not seek veterinary treatment due to financial constraints if free treatment at SPANA centres were not available.

Conclusions: Colic remains a common problem amongst working equids in Morocco. Improved knowledge of management factors associated with colic and how to recognise abdominal pain may reduce the incidence of colic and improve prognosis. Thefindings presented can be used to inform and develop owner education programmes.

Ethical animal research: The study was reviewed and approved by the Ethics Committee, School of Veterinary Medicine and Science, University of Nottingham. Informed consent for participation in the study was obtained from all owners and was delivered in the native language. No details identifying the owner were recorded. Source of funding: None. Competing interests: None declared.

APPRAISAL OF THE CURRENT EVIDENCE FOR DIAGNOSTIC TESTS THAT DIFFERENTIATE MEDICAL AND SURGICAL COLIC

Curtis, L., Cullen, T.E., England, G.C.W., Burford, J.H. and Freeman, S.L. School of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, Loughborough, Leicestershire, LE12 5RD, UK.

Email: svxli1@exmail.nottingham.ac.uk

Reasons for performing study: Early identification of surgical cases of colic is critical to improving outcome and welfare. There have been a number of studies on diagnostic tests for colic, evaluating a range of tests to differentiate between medical and surgical cases.

Objectives: To systematically review and appraise the evidence on diagnostic tests for identifying surgical colic.

Study design: Systematic review.

Methods: The primary literature search was conducted in CAB Abstracts (1910-2014), WEB of Science (1950-2014) and MEDLINE (1946-2014) using search terms relating to equine colic. Publications were assessed against inclusion and exclusion criteria, and then reviewed using the QUADAS quality assessment tool.

Results: The primary search identified 5508 publications relating to equine colic; 976 related to diagnostic tests, 29 met the inclusion criteria and were assessed using the QUADAS tool. Of these, 16 papers reported on peritoneal fluid parameters, 21 on blood parameters, 10 on blood and peritoneal parameters, 3 on physical and blood parameters and one study on urine parameters. A range of different parameters were evaluated, with the majority of tests only being evaluated in single studies. None of the studies met QUADAS criteria 1 (representative spectrum of patients), 7/29 studies met criteria 2 (description of selection criteria) and 10/29 studies met criteria 9 (description of reference standard).

Conclusions: There are currently no published studies which use appropriate methodology to assess the accuracy of a diagnostic test in differentiating medical and surgical colic. This made direct application of the QUADAS tool challenging; predominantly due to the lack of a pre mortem 'gold standard' reference diagnostic test for colic. Very few studies enrolled a randomised selection of patients and there was also a propensity to case-control study design, both increasing the risk of bias and under/overestimating diagnostic accuracy.

Ethical animal research: Not applicable. Sources of funding: Laila Curtis' studentship is funded by the School of Veterinary Medicine and Science, University of Nottingham. Tom Cullen is a Junior Clinical Training Scholar funded by the School of Veterinary Medicine and Science, University of Nottingham and Oakham Veterinary Hospital. Competing interests: None declared.

SYSTEMATIC REVIEW OF EVIDENCE FOR PLASMA AND PERITONEAL LACTATE AS A DIAGNOSTIC TEST FOR SURGICAL COLIC

Cullen, T.E., Curtis, L., England, G.C.W., Burford, J.H. and Freeman, S.L. School of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, Loughborough, Leicestershire, LE12 5RD, UK.

Email: tecullen@btinternet.com

Reason for performing study: Measurement of lactate in horses with colic has been described for over 20 years.

Objectives: To systematically review the evidence on the use of plasma and/or peritoneal lactate as a diagnostic test for identifying surgical colic.

Study design: Systematic review.

Methods: The primary literature search was conducted in CAB Abstracts (1910-2014), WEB of Science (1950-2014) and MEDLINE (1946-2014) using search terms relating to equine colic. Publications were assessed against inclusion and exclusion criteria, and then reviewed using the QUADAS scoring system.

Results: The primary search identified 5508 publications relating to colic; 32 studies related to the use of lactate in the diagnosis of colic, 2 papers met the inclusion criteria and were assessed using QUADAS. Both papers investigated the use of plasma and peritoneal lactate to identify strangulating intestinal lesions. Both were cross-sectional studies, and together they evaluated a total of 71 horses with confirmed strangulating lesions. Appraisal of the studies using the QUADAS tool was performed. Both papers met QUADAS criteria relating to study design and data analysis, but the QUADAS tool did highlight some limitations in terms of sample and control groups in both papers. Data analysis varied, with one study developing a model to predict the presence of a strangulating lesion, which included peritoneal lactate and other measurements, and the other study assessing optimal predictive values associated with concentrations of peritoneal lactate. Both studies concluded that peritoneal lactate was a more useful diagnostic test than blood lactate.

Conclusions: Despite the large numbers ofpublications reporting use of lactate, only a small number used study designs considered suitable for evaluation of diagnostic test accuracy as proposed by the Cochrane Library. Although the current evidence is limited, there is agreement on the value of peritoneal lactate as a diagnostic test for strangulating intestinal lesions.

Ethical animal research: Not applicable. Sources of funding: Tom

Cullen is a Junior Clinical Training Scholar funded by the School of Veterinary Medicine and Science, University of Nottingham and Oakham Veterinary Hospital. Laila Curtis' PhD studentship is funded by the School of Veterinary Medicine and Science, University of Nottingham. Competing interests: None declared.

MEASURES OF REDOX BALANCE IN HORSES UNDERGOING CORRECTIVE SURGERY INVOLVING STRANGULATING LESIONS OF THE SMALL INTESTINE

Bardell, D.A., Archer, D.C. and Milner, P.I.

The Philip Leverhulme Equine Hospital, School of Veterinary Science, University of Liverpool, UK. Email: bertie@liverpool.ac.uk

Reasons for performing study: Colic remains a life-threatening condition in the horse. Ischaemia and reperfusion following correction of small intestinal strangulation may produce oxidative stress. The ability to withstand oxidative stress depends on antioxidant levels and may be linked to horse survival.

Objectives: To measure peripheral antioxidant levels in horses undergoing exploratory laparotomy with small intestinal strangulation.

Study design: Case-control study.

Methods: Blood and plasma were collected from horses undergoing exploratory laparotomy for small intestinal strangulation and stored at -80°C. Controls involved non-colic horses. Total plasma glutathione was measured spectrophotometrically at 412 nm using the 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB, Ellman's reagent) reaction. Samples containing scavenger (to remove reduced glutathione, GSH) were used to measure oxidised glutathione (GSSG). Glutathione reductase (GR) activity (u/l) was measured as the rate of GSH production at 412 nm. Glutathione

peroxidise (GPx) activity (u/l) was measured as the change in optical density (340 nm) following the consumption of NADPH after GSSG production. All assays were purchased from BioAssay Systems (Hayward, California). Clinical data including arterial blood gas analysis were collected on admission.

Results: Glutathione reductase activity in horses with strangulating small intestinal lesions was significantly reduced compared to control horses (12.2 ± 1.1 u/l vs. 15.9 ± 0.8 u/l, P = 0.03, n = 6) whereas GPx activity did not significantly differ between colic and control horses (155.7 ± 48.7 u/l vs. 167.3 ± 30.1 u/l, P = 0.84, n = 6). Total glutathione, reduced or oxidised glutathione did not differ significantly between control and colic horses. A positive correlation existed between GR activity and Ca2+ (r = 0.93) and K+ (r = 0.75) whereas a strong negative correlation was present between GR activity and HCO3- (r = -0.92) and PaCO2 (r = -0.96).

Conclusions: Reduced plasma glutathione reductase activity with small intestinal strangulation indicates oxidative stress and may be related to systemic electrolyte/bicarbonate abnormalities.

Ethical animal research: Study approval No. VREC219a. Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: Supported by the School of Veterinary Sciences, University of Liverpool. Competing interests: None declared.

EVALUATION OF DEXAMETHASONE FOR THE PREVENTION OF POST OPERATIVE ILEUS

McGovern, K.F., James, F.M., O'Neill, H.D. and Bladon, B.M. Donnington Grove Veterinary Group, Oxford Road, Newbury, Berkshire, RG14 2JB, UK.

Email: kfmcgovern@gmail.com

Reasons for performing study: Inflammation is key in the development of post operative ileus in rodents, with a similar pathogenesis likely occurring in other species. Dexamethasone reduces inflammation and therefore could help reduce post operative ileus in the horse.

Objectives: To determine if dexamethasone reduces post operative ileus in horses with small intestinal disease, and assess the effect on incisional health and short-term survival.

Study design: Retrospective case series.

Methods: Fifteen horses that underwent small intestinal resection and anastomosis were given 0.1 mg/kg bwt dexamethasone intravenously during surgery (DEX). Data from a comparable number of horses that did not receive dexamethasone (NoDEX) was collected retrospectively and sequentially Horses were matched for the type of resection performed. Fisher's Exact and Student's t tests were used for data analysis.

Results: There was no significant difference in the amount of nasogastric reflux (litres) (DEX 8.06 ± 17.12, NoDEX 10.02 ± 24.03, P = 0.39) produced or in the number of horses that produced nasogastric reflux post operatively. There was no difference in survival to discharge. The severity of incisional discharge/infection was significantly different between groups when scored 0-3 (0 being no discharge and 3 being severe discharge/infection), (P = 0.01), in favour of DEX (2/15 horses affected) vs. NoDEX (7/15).

Conclusions: Dexamethasone did not appear to have a beneficial effect on the incidence of post-operative ileus. Administration of a single dose of dexamethasone does not appear to have a detrimental effect on short-term survival or on incisional complications.

Ethical animal research: Research ethics committee oversight not currently required by this conference: procedures were performed as part of clinical investigations. Explicit owner informed consent for participation in this study was not stated. Source of funding: None. Competing interests: None declared.

IS THERE EVIDENCE FOR FUNCTIONAL 5-HYDROXYTRYPTAMINE 4 (5-HT4) RECEPTORS IN THE EQUINE JEJUNUM? AN IN VITRO STUDY TO EXPLORE OPTIONS FOR USE OF HUMAN PROKINETIC DRUGS, ACTING AS 5-HT4 RECEPTORS, IN HORSES

+Delesalle, C.J.G., *Callens, C., §Van Colen, I. and §Lefebvre, R.A. fGhent University, Faculty of Veterinary Medicine, Department of Comparative Physiology, Belgium; *Ghent University, Faculty of Bioscience Engineering, Kortrijk, Belgium; sGhent University, Heymans Institute of Pharmacology, Faculty of Medicine and Health Sciences, Belgium.

Email: c.j.g.delesalle@uu.nl

Reasons for performing study: Selective 5-HT4 receptor agonists such as prucalopride are used as human prokinetics, since activation of 5-HT4 receptors on intestinal cholinergic neurons facilitates acetylcholine release. 5-HT4 receptors, linked to adenylyl cyclase, act via generation of cAMP. None of the 4 in vitro studies on 5-HT in horses provided evidence for neuronal 5-HT4 receptors, but none used the protocol as described in human studies [1-4].

Objectives: To investigate whether functional 5-HT4 receptors are present in the equine small intestine.

Study design and methods: In vitro organ bath set up, applying electrical field stimulation (EFS) in longitudinal and circular smooth muscle strips.

Results: Results were similar in both muscle layers. In the presence of

0.3.mmol/l NG-Nitro-L-arginine methyl ester and 0.3 |imol/l apamine, excluding effects of the inhibitory transmitters NO and ATP, EFS induced voltage-dependent on-contractions; these were neurogenic as they were abolished by 3 |imol/l tetrodotoxin. At a voltage inducing 50% of the maximal amplitude, the submaximal EFS-induced contractions were cholinergic as atropine (1 |imol/l) abolished them. Prucalopride (0.3 |imol/l) did not increase the amplitude of these submaximal EFS-induced contractions. Even in the presence of the nonselective phosphodiesterase inhibitor IBMX, previously shown to enhance the effect of neuronal 5-HT4 receptors by inhibiting breakdown of their 2nd messenger cAMP [5], prucalopride (3 |mol/l) had no influence. Also 5-HT (10 |mol/l), a full agonist at 5-HT4 receptors, tested in the presence of methysergide and granisetron to exclude interaction with other 5-HT receptor subtypes, did not enhance EFS-induced submaximal contractions.

Conclusions: There is no evidence for presence of 5-HT4 receptors on the cholinergic neurons of the equine small intestine. These results question the application of 5-HT4 prokinetic drugs in horses.

Ethical animal research: Research ethics committee oversight not currently required by this conference: the study was performed on material collected at an abattoir. Sources of funding: None. Competing interests: None declared.

References

1. Weiss, R., Abel, D., Scholtysik, G., Straub, R. and Mevissen, M. (2002) 5-Hydroxytryptamine mediated contractions in isolated preparations of equine ileum and pelvic flexure: pharmacological characterization of a new 5-HT(4) agonist. J. Vet. Pharmacol. Ther. 25,49-58.

2. Nieto, J.E., Snyder, J.R., Kollias-Baker, C. and Stanley, S. (2000) In vitro effects of 5-hydroxytryptamine and cisapride on the circular smooth muscle of the jejunum of horses. Am. J. Vet. Res. 61,1561-1565.

3. Delesalle, C., Deprez, P., Schuurkes, J.A. and Lefebvre, R.A. (2006) Contractile effects of 5-hydroxytryptamine and 5-carboxamidotryptamine in the equine jejunum. Br. J. Pharmacol. 147,23-35.

4. Prause, A.S., Guionaud, C.T., Stoffel, M.H., Portier, C.J. and Mevissen, M. (2010) Expression and function of 5-hydroxytryptamine 4 receptors in smooth muscle preparations from the duodenum, ileum, and pelvic flexure of horses without gastrointestinal tract disease. Am. J. Vet. Res. 71,1432-1442.

Winner of Voorjaarsdagen Award 2015

ETHMOIDAL INFECTION WITH ASPERGILLUS SPP. IN 3 HORSES: SUCCESSFUL TREATMENT BY TRANSENDOSCOPIC REMOVAL OF MYCOTIC PLAQUES ALONE OR IN COMBINATION WITH SYSTEMIC ITRACONAZOLE

Theelen, M.J.P., Siegers, E.W. and Ensink, J.M.

Utrecht University, Faculty of Veterinary Medicine, Department of Equine Sciences, Yalelaan 112,3584CM Utrecht, The Netherlands. Email: m.j.p.theelen@uu.nl

Reasons for performing study: Ethmoidal infection with Aspergillus spp. is rarely reported in horses. Three horses suffering from unilateral infection with Aspergillus spp. of the ethmoid with varying underlying conditions are described.

Study design: Case series.

Methods: Diagnosis was made by endoscopy of the ethmoid (presence of white mycotic plaques on a layer of thick yellow mucus) and confirmed by fungal culture (A. fumigatus) and/or cytology. Clinical details and outcome were obtained from the medical records and by contacting owners.

Results: Horse 1 and 2 had a progressive ethmoid haematoma (PEH) and had been treated for over 5 months with repeated formalin injections (one horse after initial surgical debulking of the PEH that also invaded the maxillary and sphenopalatine sinuses) before the infection with Aspergillus was diagnosed. The third horse, presented with poor performance and nasal discharge, had congenitally abnormal anatomy of the right dorsal nasal passage and right ethmoids. In the 2 horses with PEH the mycotic plaques were removed transendoscopically successfully. After 6 weeks the infection was no longer present at endoscopy in both horses (follow-up endoscopy: Horse 1 no relapse >16 months and Horse 2 no relapse >7 months). In the third horse, it was not possible to remove all mycotic plaques, therefore systemic treatment with itraconazole (3 mg/kg bwt q. 12 h for 8 weeks orally) was started. After 8 weeks, the clinical signs had resolved and endoscopy showed that the Aspergillus infection had cleared (follow-up: no relapse >14 months). No side effects were seen with systemic itraconazole treatment.

Conclusions: In horses with underlying ethmoidal conditions, secondary infection with Aspergillus spp. may occur. Transendoscopic removal of the mycotic plaques alone may be successful and if this approach is not feasible or unsuccessful, systemic treatment with itraconazole can be considered.

Ethical animal research: Research ethics committee oversight not currently required by this conference: retrospective study of clinical records. Owners gave informed consent for their horses' inclusion in the study. Source of funding: Utrecht University. Competing interests: None declared.

IOHEXOL AS A MARKER OF INTESTINAL PERMEABILITY IN THE HORSE

fKoskinen, M.J., *Hewetson, M. and §Poytakangas, M.R. fSavo Equine Hospital, Hingunniementie 98, 74700 Kiuruvesi, Finland; *Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa; §Department of Production Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, POBox57, 00014 Helsinki, Finland.

Email: milja.koskinen@helsinki.fi

Reasons for performing study: Infiltrative disease of the intestine is an important cause of weight loss in the horse. Infiltration of inflammatory or neoplastic cells into the intestinal wall and intestinal fibrosis cause changes in the integrity of the intestinal wall. This may lead to altered intestinal permeability which can be measured using the contrast medium iohexol.

Objectives: To determine if iohexol intestinal permeability, as evaluated by serum iohexol concentration, could be used to differentiate between healthy horses and horses with infiltrative disease of the large colon.

Study design: Prospective non-randomised controlled clinical trial.

Methods: Six healthy adult horses and 4 horses with chronic infiltrative disease of the large colon were used in the study. Infiltrative disease was confirmed on postmortem in all cases, and included alimentary lymphoma and mycobacterial granulomatous enterocolitis. Following a 16-h fast, each horse was dosed with 1.0 ml/kg bwt of iohexol as a 10% solution via nasogastric intubation. Blood samples were collected at 0, 30, 60, 120, 180, 240, 300, 360, 420 and 480 min after dosing. Iohexol concentration was determined using HPLC-UV and the differences between the groups were analysed with a repeated measures ANOVA.

Results: There was a statistically significant difference in iohexol serum concentration between the diseased and nondiseased horses (P = 0.001). The overall difference in the mean iohexol concentration between the 2 groups was 6.07 (95% CI 3.19-8.96) |g/ml, howeverthere appeared to be a trend towards increasing difference at later time points (240, 300, 360 min).

Conclusions: The iohexol permeability test has potential as a diagnostic tool for estimation of intestinal permeability in horses with infiltrative intestinal disease. Further studies are warranted to determine whetherthe test can be used to determine the site of intestinal pathology, predict the prognosis and potentially evaluate the response to treatment.

Acknowledgements: The authors thank Professor Riitta-Mari Tulamo and Professor Thomas Spillmann and the staff of Equine College Ypaja and the University of Helsinki Equine Teaching Hospital. The cooperation of horse owners is gratefully acknowledged.

Ethical animal research: The study protocol was approved by the National Animal Experiment Board of Finland (Elainkoelautakunta ELLA, Request for Animal Experiments, ref. no. ESAVI-2010-06567/Ym-23). For client-owned animals, owner informed consent was obtained. Source of funding: This study was funded by the Faculty of Veterinary Medicine, University of Helsinki, Finland. Competing interests: None declared.

DIAGNOSTIC ACCURACY OF BLOOD SUCROSE AS A SCREENING TEST FOR DIAGNOSIS OF GASTRIC ULCERATION IN ADULT HORSES

fHewetson, M., *Sykes, B.W., §Hallowell, G. and fTulamo, R.M. ^Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, PO Box 57, 00014 Helsinki, Finland; *BW Sykes Consultancy, 51 Fridays Creek Road, Upper Orara, New South Wales 2450, Australia; §School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Leicestershire, LE125RD, UK. Email: michael.hewetson@helsinki.fi

Reasons for performing study: Gastric ulceration is an important cause of morbidity in horses. Currently, gastroscopy is the only reliable antemortem method for definitive diagnosis; however, it is unsuitable as a screening test because it is expensive, invasive and time-consuming. Sucrose permeability testing represents a simple, economical, non-invasive alternative to gastroscopy for screening purposes, and the feasibility of this approach in the horse has been reported [1].

Objectives: To determine the diagnostic accuracy of blood sucrose as a screening test for gastric ulceration.

Study design: Cross-sectional design.

Methods: One hundred and one adult horses with and without naturally occurring gastric ulcers were studied. The diagnostic accuracy of blood sucrose for detection of gastric ulcers at 45 and 90 min after administration of 1 g/kg bwt of sucrose via nasogastric intubation was assessed with ROC curves and calculating the area under the curve (AUC). Sucrose concentration in blood was compared with gastroscopy as the gold standard; and sensitivities (Se) and specificities (Sp) were calculated across a range of sucrose concentrations. Cut-off values were selected manually to optimise sensitivity.

Results: The prevalence of gastric ulcers was 83%. The AUC ± 95% CI for blood sucrose concentration when used to distinguish between horses with and without gastric ulcers at 45 and 90 min was 0.592 (0.441-0.744) and 0.615 (0.469-0.761) respectively. Sucrose concentrations of 4.70 |imol/l at 45 min; and 4.57 |imol/l at 90 min were selected as optimal cut-offs. Using these cut-offs, Se ranged from 64.4% to 77%; and Sp ranged from 42.9% to 50%.

Conclusions: Blood sucrose is neither a sensitive nor specific test for detecting gastric ulcers in adult horses with naturally occurring ulcers.

Acknowledgements: We thank Sandy Love, Satu Sankari, Anna-Maija Virtala, Noah Cohen, Allen Rousell, Kaisa Aaltonen, Anne Sjoholm and Jouni Junnila.

Ethical animal research: The study protocol was approved by the National Animal Experiment Board of Finland (Elainkoelautakunta ELLA). For client-owned animals, the informed consent of the owner was obtained. Source of funding: This study was funded by the Faculty of Veterinary Medicine, University of Helsinki, Finland. Competing interests: None declared.

Reference

1. Hewetson, M., Cohen, N.D., Love, S., Buddington, R.K., Holmes, W,. Innocent, G.T. and Roussel, A.J. (2006) Sucrose concentration in blood: a new method for assessment of gastric permeability in horses with gastric ulceration. J. Vet. Intern. Med. 20,388-394.

DIAGNOSTIC VALUE OF GASTRIC MUCOSAL BIOPSIES IN HORSES WITH GLANDULAR DISEASE

Crumpton, S.M., Baiker, K., Hallowell, G.D., Habershon-Butcher, J.L. and Bowen, I.M.

School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Loughborough, Leicestershire, UK. Email: svysmcr@exmail.nottingham.ac.uk

Reasons for performing study: Equine gastric glandular disease (EGGD) is a common condition, for which the underlying pathophysiology is undetermined. Endoscopic mucosal biopsies have been proposed as a method for adapting therapy.

Objectives: To evaluate diagnostic information obtained from endoscopic mucosal biopsies.

Study design: Prospective, experimental study.

Methods: Twenty-one horses undergoing elective humane slaughter were subjected to gross examination of the glandular mucosa. Glandular pathology was graded using EGUS Council guidelines from digital camera images. Mucosal biopsies were obtained using a 'single-bite' (1.8 mm; A and 2.4 mm; B) or 'double bite' technique (2.4 mm; C) using endoscopic biopsy instruments. Tissue was formalin fixed, processed and stained using standard protocols. Inflammatory infiltrates visualised histologically were graded (mild, moderate or severe) and compared with ulcer grade. Full thickness biopsies were also obtained adjacent to the biopsy site and of other visual lesions and inflammatory cell counts were compared with mucosal biopsies using ICC.

Results: Full thickness samples were artefact free and allowed visualisation of all layers. Mucosal biopsy samples contained mucosa in all samples, submucosa in 55% (C), 61% (A) and 66% (B) of samples and glands in 50% (B), 66% (A) and 100% (C). Samples from A were too small for histological assessment (33%) and tissue damage was commonly seen in A and B (n = 8 and n = 10) when compared with C (n = 3). Horses with normal glandular appearance (grade 0; n = 7) mostly demonstrated mild gastritis (n = 5). Severe gastritis was identified in mild EGGD (grade 1/2), whilst mild and moderate gastritis was identified in all EGGD grades. There was no histological evidence of ulceration or erosion. There was poor agreement between cell numbers and sampling techniques (ICC<0.29).

Conclusions: These data show lack of ulcerative pathology and instead inflammation in EGGD. Lesion appearance is a poor indicator of underlying severity. Mucosal biopsies offer limited value in predicting underlying disease.

Ethical animal research: This study was approved by the University of Nottingham Ethics and Welfare Committee. The study was performed on material collected at an abattoir. Source of funding: None. Competing interests: None declared.

UNDERSTANDING INTESTINAL MICROBIOTA IN EQUINE GRASS SICKNESS: NEXT GENERATION SEQUENCING OF FAECAL BACTERIAL DNA

+Leng, J., +Proudman, C., *Blow, F., *Darby, A. and §Swann, J. fSchool of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU27TE, UK; *School of Biological Sciences, University of Liverpool, Crown Street, Liverpool, L69 7ZB, UK; sDepartment of Food and Nutritional Sciences, University of Reading, Whiteknights, Reading, RG6 6AP, UK. Email: j.leng@surrey.ac.uk

Reasons for performing study: The bacteria Clostridium botulinum has been associated with equine grass sickness (EGS); however, the effect on the wider horse's gut microbiome is currently unknown.

Objectives: To characterise the bacterial dysbiosis that occurs within the gut microbiome of horses with EGS and to identify and quantify Clostridium botulinum within the faecal microbiota of the affected horses.

Study design: Case-control study.

Methods: Faecal samples were collected from horses with a histo-logical diagnosis of EGS and matched controls. Faecal bacterial DNA was extracted and sequenced to characterise the microbial communities in the group. Faecal samples were collected from a total of 33 horses over2 years. This included 13 EGS cases, 14 matched controls and 6 hospital controls. Faecal bacterial DNA was extracted from samples and the v4 region of the bacterial 16S rRNA gene was amplified. DNA was sequenced on the MiSeq platform and data was analysed using QIIME. Differences in community profile between the 3 groups of horses were identified using linear discriminant analysis effect size (LEfSe) method.

Results: There was a significant increase in Bacteroidetes and a decrease in Firmicutes bacteria in horses with EGS compared to the 2 control groups. Discriminant analysis identified bacterial genera Desulphovibrio and Veillonella and the bacterial species Veillonellaparvula as increased in abundance. There was no noticeable increase in C. botulinum in the faecal microbiome of EGS horses in this study.

Conclusions: The dysbiosis characterised by bacterial sequencing showed a similar shift to that identified previously in colitis horses and human inflammatory bowel disease. It is currently unclear how Verrucomicrobia bacteria are linked to grass sickness.

Ethical animal research: The study was approved by The University of Liverpool ethics committee. Owner informed consent was obtained before sampling. Sources of funding: The Equine Grass Sickness Fund and The University of Reading. Competing interests: None declared.

EQUINE CYATHOSTOMINAE CAN DEVELOP TO INFECTIVE THIRD STAGE LARVAE ON STRAW BEDDING

+McGirr, E.C., *Denwood, M.J., +McGoldrick, J. and +Love, S. fSchool of Veterinary Medicine, University of Glasgow, Bearsden Road, Glasgow, G61 1QH, UK; *Section for Animal Welfare and Disease Control, University of Copenhagen, Grnnnegardsvej 8, 1870 Frederiksberg C, Denmark.

Email: eoghan_mcgirr@hotmail.com

Reasons for performing study: To determine whether horses could become infected with cyathostomins when bedded in deep litter straw.

Objectives: The specific objective of the study was to determine whether cyathostomin eggs could hatch and develop to infective larval stages on straw bedding.

Study design: Experimental study.

Methods: Four horticultural incubators were set up to simulate 3 straw bedding scenarios, and one grass turf control. Faeces were placed on 12 plots, and larval recoveries performed on samples of straw/grass over a 17-day period. The plots within incubators A, B, and C contained dry straw, watered straw, and deep litter straw, respectively. Plot 1 of each incubator contained a faecal pat of a horse that tested negative for strongyle eggs -these were to serve as negative control plots. Plots 2 and 3 of each incubator contained a faecal pat from horses that had average faecal worm egg counts (FWEC) of 269 epg and 921 epg, respectively. A thermostat within each incubator was set to maintain an environmental temperature of approximately 20°C.

Results: No L3 larvae were recovered from the control plots of each incubator, and none were recovered from any of the plots within Incubator A. L3 larvae were first detected on plots 2 and 3 of Incubator B on Day 8, and on plot 3 of incubators C and D on Day 10.

Conclusions: It is evident that equine Cyathostominae can develop to infective L3 larvae on straw bedding, but only when the straw is moist. Therefore, it may be speculated that a horse bedded in deep litter straw may become infected by ingesting the infective L3 larvae contaminating the straw.

Ethical animal research: Not applicable. Source of funding: E C.

McGirr was supported by a World Horse Welfare Undergraduate Bursary 2014. Competing interests: None declared.

A RETROSPECTIVE DENTAL STUDY ON 5334 HORSES IN GENERAL PRACTICE

Duncanson, G.

Blackthorn Lodge, Crostwick, Norwich, NR12 7BG, UK. Email: vetdunc@btinternet.com

Reasons for performing study: Rasping of sharp enamel points (SEPs) is the most common procedure performed at routine dental examinations; however, there is little evidence to prove the true clinical significance of SEPs [1]. Maxillary SEPs are thought to cause buccal ulceration and pain on external palpation of the cheeks. Mandibular SEPs are thought to cause lingual ulceration.

Objectives: To examine associations between the presence of SEPs on the cheek teeth rows and the presence of pain on palpation of the cheeks and buccal and/or lingual ulceration.

Study design: Retrospective clinical case series.

Methods: Clinical records of routine dental examination performed by 8 veterinary surgeons in a single first opinion practice were examined. Presence ofSEPs, buccal and/or lingual ulceration and pain on palpation of the cheeks (externally) were recorded. Chi squared tests were used to examine whether horses exhibiting pain on palpation or oral ulceration were significantly more likely to have SEPs present.

Results: Prevalence of buccal SEPs was 84.8% and prevalence of lingual SEPs was 84.3%. Five hundred and forty-eight horses (6.0%) had signs of pain on palpation. Prevalence of buccal ulceration was 5.9%. In contrast, only 0.2% of horses had visible lingual ulceration. Buccal ulceration and pain on palpation were significantly associated with presence of buccal SEPs (P<0.001 for both). Lingual ulceration was not significantly associated with lingual SEPs (P<0.0001).

Conclusions: Buccal SEPs are common and often result in pain and buccal ulceration. Routine rasping would appear to be justified. Lingual

SEPs are common but rarely cause lingual ulceration. The value of routine rasping of lingual SEPs is therefore questionable.

Ethical animal research: Research ethics committee oversight not currently required by this conference: retrospective study of clinical records. Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: None. Competing interests: None declared.

Reference

1. Duncanson, G.R. (2010) Does regular dental treatment influence the long-term dental health of the horse? RCVS Fellowship Thesis.

HEAD AND PELVIC MOVEMENT ASYMMETRIES AT TROT IN RIDING HORSES PERCEIVED AS SOUND BY THEIR OWNER

tRhodin, M., tEgenvall, A., fAndersen, P.H. and *Pfau, T. department of Clinical Sciences, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden; *Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield, AL9 7TA, UK. Email: marie.rhodin@slu.se

Reasons for performing study: Recent studies evaluating owner sound horses have identified a large proportion of horses with motion asymmetries but the prevalence, type and magnitude of asymmetries have not been investigated. The increasing use of objective lameness evaluation necessitates a further characterisation of the differences between lameness and motion asymmetries.

Objectives: To investigate prevalence, and quantify type and magnitude of motion asymmetries during straight-line trot in riding horses, perceived sound by their owners.

Study design: Cross-sectional prospective study.

Methods: Vertical head and pelvic movement symmetry was measured in 220 Warmblood riding horses, all functioning in daily work and considered sound by their owners; 100 of these individuals had been included in a previous report [1]. Body-mounted uni-axial accelerometers were used and differences between maximum and minimum head (HDmax, HDmin) and pelvic (PDmax, PDmin) vertical displacement between left and right forelimb and hindlimb stances were calculated during straight-line trot. Previously used symmetry thresholds (absolute differences >6 mm for the head and >3 mm for the pelvic variables) were used.

Results: The thresholds for symmetry were exceeded for 159 horses (72%) for at least one variable, HDmax (n = 41, mean 12.7 mm, s.d. 5.5), HDmin (n = 58, mean 14.3 mm, s.d. 7.1), PDmax (n = 87, mean 6.5 mm, s.d. 3.10), PDmin (n = 77, mean 5.7 mm, s.d. 2.1). Contralateral and ipsilateral concurrent fore- and hindlimb asymmetries were detected in 41 and 49 horses, respectively.

Conclusions: A surprisingly large proportion (72%) of horses perceived as sound by their owner showed movement asymmetries during straight-line trot. It is not known to what extent these asymmetries are related to pain or mechanical abnormalities as opposed to 'normal variation' and this leads to 2 potential welfare problems - either too many horses in training are actually 'lame' or many horses categorised as 'lame' have no locomotor system disease.

Ethical animal research: This study was conducted within guidelines of the participating sites institutional animal care and use procedures (C 206/10, C48/13) and informed consent for data collection was obtained from the horse owners prior to the study. Source of funding: None. Competing interests: None declared.

Reference

1. Rhodin, M., Roepstorff, L., French, A., Keegan, K.G., Pfau, T. and Egenvall, A. (2015) Head and pelvic movement asymmetry during lungeing in horses with symmetrical movement on the straight. Equine Vet. J. Epub ahead of print. DOI: 10.1111/evj.12446.

OBJECTIVE ASSESSMENT OF BACK KINEMATICS AND MOVEMENT ASYMMETRY IN HORSES: EFFECT OF ELASTIC RESISTANCE BAND TRAINING

+Simons, V, +Weller, R., *Stubbs, N.C., §Rombach, N. and +Pfau, T. fDepartment of Clinical Science and Services, The Royal Veterinary College, University of London, North Mymms, Hatfield, AL9 7TA, UK; *Private Practice, Michigan, USA; sPrivate Practice, California, USA. Email: vesimons@rvc.ac.uk

Reasons for performing study: Training and rehabilitation techniques which improve core muscle strength are beneficial for improvement of dynamic stability of the equine vertebral column. The Equiband™ system, consisting of resistance bands attached to a customised saddle pad, is suggested to provide constant proprioceptive feedback during motion to encourage recruitment of abdominal and hindquarter musculature.

Objectives: To quantify the effect of the Equiband™ system on back kinematics and movement symmetry.

Study design: Longitudinal intervention study.

Methods: Quantitative analysis of back movement and gait symmetry before/after a 4-week exercise programme. Inertial sensor data was collected from 7 horses at Weeks 0 and 4 of a fixed exercise protocol. Analysis with and without the Equiband™ system was completed at trot in hand on a hard surface, and for both reins on the lunge on a soft surface. Six back kinematic and 3 movement symmetry parameters were calculated according to published methods. Movement symmetry values were side-corrected to allow comparison between reins on the lunge. A mixed model (P<0.05) evaluated the effects of the Equiband™ system overtime, and trotting direction on back kinematic and movement symmetry parameters.

Results: The Equiband™ system significantly reduced (all P<0.02) roll, pitch and mediolateral displacement in the cranial-mid thoracic region. Across all horses, back displacement and range of motion values were significantly greater (P<0.01) on the lunge than in a straight line, movement symmetry was consistent with having corrected all horses to be left-sided.

Conclusion: Preliminary results suggest the Equiband™ system may aid dynamic stabilisation of the vertebral column.

Ethical animal research: This study was authorised by the Ethics and Welfare Committee of the Royal Veterinary College, London (URN Approval Number 1238). Written consent was obtained from the owner/keeper of each animal. Source of funding: Royal Veterinary College. Competing interests: N.C. Stubbs and N. Rombach developed the Equiband™ system. The remaining authors have no competing interests.

THORACOLUMBAR MOVEMENT IN SOUND HORSES TROTTING IN HAND AND ON THE LUNGE

+Greve, L., +Dyson, S. and *Pfau, T.

fCentre for Equine Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, CB8 7UU, UK; *The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, UK. Email: line.greve@aht.org.uk

Reasons for performing study: Lameness negatively affects the welfare of horses; it often coexists with thoracolumbar pain. The mechanisms linking the two are not well understood.

Objectives: To document thoracolumbar movement in subjectively sound horses comparing straight lines with circles on left and right reins; to relate these observations to the objectively determined symmetry/asymmetry of hindlimb gait.

Study design: Cross-sectional study.

Methods: Fourteen non-lame horses were trotted in straight lines and lunged on a 10 m diameter circle on left and right reins and inertial sensor data collected at landmarks: withers, 13th (T13) and 18th thoracic vertebrae, 3rd lumbar vertebra, tubera sacrale, leftand right tubera coxae. Data were processed using published methods [1]; pitch and roll, dorsoventral and lateral motion and symmetry within each stride were assessed.

Results: Dorsoventral motion during one stride had a sinusoidal pattern with 2 oscillations. The greatest amplitude and symmetry (119 ± 4 mm, 96 ± 1% in straight lines vs. 127 ± 5 mm, 94 ± 1% in circles) occurred atT13. Circles induced greater rotation around the transverse axis (>1.3°, P = 0.002) and movement in a lateral direction (>16 mm P = 0.002), greater dorsoventral amplitude and asymmetry; however, the latter differences were nonsignificant. There were no significant differences between reins. The difference in the left and right hindlimb stance phases and the 2 oscillations of the thoracolumbar were significantly associated. Greater circle-induced upward movement of a tuber coxae during the contralateral hindlimb stance was associated with greater circle-induced asymmetry of the 2 oscillations of the thoracolumbar (P = 0.04).

Conclusions: Moving on a circle induces measurable changes in thoracolumbar movement compared with moving in straight lines, associated with alterations in the hindlimb gait.

Ethical animal research: The study was approved by the Ethical Review Committee of the Animal Health Trust. Owners gave informed consent for their horses' inclusion in the study. Source of funding: RVC PhD funding of Line Greve. Competing interests: None declared.

Reference

1. Pfau, T., Witte, T.H. and Wilson, A.M. (2005) A method for deriving displacement data during cyclical movement using an inertial sensor. J. Expl. Biol. 208, 2503-2514.

AN IN VITRO INVESTIGATION OF THE EFFECT OF CURVE RUNNING ON EQUINE DISTAL LIMB TENDON STRAIN

Parkes, R.S.V., Witte, T.H., Pfau, T. and Weller, R.

Structure and Motion Laboratory, Royal Veterinary College, Hawkshead

Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, UK.

Email: rparkes@rvc.ac.uk

Reasons for performing study: Horses run on curves during training and competition, and are often trotted in circles to assist lameness

diagnosis. The effects of moving on a curve on tendon strain in the distal limb are not known.

Objectives: To investigate the effect of curve running on the tendons and ligaments of the equine distal limb.

Study design: Controlled experimental study.

Methods: Cadaver forelimbs from 6 Thoroughbred horses were loaded on a forceplate using a hydraulic ram. Limbs were loaded to 17-33 N/kg on a flat surface and with medial and lateral wooden wedges under the hoof to simulate curve running with the limb being on the inside and outside of a curve, respectively. Tendon length was measured for the superficial and deep digital flexor tendons (SDFT and DDFT), accessory ligament of the DDFT (ALDDFT), the suspensory ligament body (SL) and the medial and lateral suspensory ligament branches (SBM and SBL) using motion capture. A mixed effects model was used for data analysis.

Results: Under most loading conditions SL was under most strain and DDFT least. For a medial 15° wedge SDFT was under 0.4% greater load than SL (P = 0.04). SBM was under 0.48% greater strain than SBL with a lateral 20° wedge (P = 0.01), and SBL was under 1.37% greater strain than SBM with a medial 20° wedge (P<0.01).

Conclusions: Curve running leads to increasing and asymmetrical strain on the suspensory ligament branches. This difference is unlikely to be sufficient to cause injury, but may assist lameness diagnosis.

Ethical animal research: Research ethics committee oversight not currently required by this conference: the study was performed on material collected at an abattoir. Source of funding: R. Parkes is undertaking a PhD funded by the Horserace Betting Levy Board. Competing interests: None declared.

GONIOMETRIC MEASUREMENT OF LIMB STIFFNESS: VALIDATION OF A POTENTIAL PREDICTOR OF TENDON HEALING

+Tucker, R.,*Jacklin, B.D., +Gillespie, S., +Vaughan, L., +Fiske-Jackson, A.R. and +Smith, R.K.

fRoyal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK; *Newmarket Equine Hospital, Cambridge Road, Newmarket, Suffolk, CB8 0FG, UK. Email: rtucker@rvc.ac.uk

Reasons for performing study: Injury to the superficial digital flexor tendon (SDFT) is common in equids, with a high risk of re-injury associated with changes in tendon stiffness. In vivo measurement of limb stiffness has been shown to correlate with tendon stiffness after injury [1] but requires kinematic analysis which is impractical in a clinical setting. We have developed a simple system for measuring limb stiffness statically, which could be used as a tool for monitoring SDFT healing.

Objectives: To validate a goniometric measurement of limb stiffness.

Study design: Cross sectional study.

Methods: Initially, forelimb stiffness indices were determined at the walk for 6 equids using a validated kinematic analysis [1]. Limb stiffness indices were then calculated using portable floor scales to record ground reaction force (GRF), and an electrogoniometer to record metacarpophalangeal joint angle. Goniometric limb stiffness indices were subsequently measured in 11 horses ranging from 2 to 20 years of age, with no clinical evidence of SDFT injury. Strength and significance of correlation and agreement between the measurement methods was assessed and association between limb stiffness, limb (left vs. right), weight and age of horse and were calculated.

Results: There were strong positive correlations between GRF and joint angle (R2 = 0.98) and between the static and kinematic methods (R = 0.78, P<0.01). There was a positive correlation between limb stiffness and weight (R2 = 0.85, P<0.01), but no association with age or limb.

Conclusions: This study validated the measurement of limb stiffness in a clinical setting. The positive correlation of limb stiffness and weight supports the theory of an optimised limb spring [2] for energy-efficient cursorial locomotion which may, in turn, provide a clinically-relevant measure of running efficiency and therefore the quality of tendon healing post injury.

Ethical animal research: Owner consent was obtained. Source of funding: None. Competing interests: None declared.

References

1. Dakin,S.G.,Jespers, K., Warner, S., O'Hara, L.K., Dudhia, J., Goodship, A.E., Wilson, A.M. and Smith, R.K.W. (2011) The relationship between in vivo limb and in vitro tendon mechanics after injury: A potential novel clinical tool for monitoring tendon repair. Equine Vet. J. 43, 418-423.

2. McGuigan, P. and Wilson, A.M. (2003) The effect of gait and digital flexor muscle activation on limb compliance in the forelimb of the horse Equus caballus. J. Exp. Biol. 206,1325-1336.

WHAT EFFECT DOES MEDIUM AND EXTENDED TROT HAVE ON THE KINEMATICS OF THE FORELIMB IN DRESSAGE HORSES?

Walker, V.A., Tranquille, C.A., Dyson, S.J., Newton, R. and Murray, R.C. Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, CB8 7UU, UK.

Email: vawalker87@gmail.com

Reasons for performing study: Metacarpophalangeal joint hyperextension overload is increasingly being recognised in dressage horses and, like forelimb suspensory ligament injury, tends to be seen in horses with extravagant trot steps. However, there is limited understanding of the effects of different paces within the trot on forelimb movement, therefore it is difficult to advise rationally on prevention or management of these types of injury.

Objectives: To compare forelimb kinematics of collected and medium or extended trot in dressage horses.

Study design: Prospective study.

Methods: Twenty mixed-breed dressage horses (age 9 ± 4 years; height 168 ± 6 cm; weight 600 ± 63 kg; median competition level = advanced medium) were tested at collected and medium/extended trot (age and training level dependent) in a straight line on an artificial surface ridden by their own rider at sitting trot. Four strides of each pace were recorded using high speed motion capture (240 Hz). Markers were placed on the horses' forelimbs at predetermined anatomical sites. Fetlock, carpus, elbow and shoulder angles were derived at midstance. Descriptive statistics and mixed effect multilevel regression analyses were performed on the data.

Results: Fetlock extension angle was significantly increased at medium compared with collected trot (coefficient: 5.70; CI 2.58-8.82; P<0.01) and extended compared with collected trot (coefficient: 8.59; CI 5.16-12.02; P<0.01). Fetlock extension angle was significantly increased when carpus extension angle (coefficient: 0.61; CI = 0.4-0.82; P<0.01) and shoulder flexion angle were increased (coefficient: 0.18; CI 0.01-0.33; P<0.05).

Conclusions: Fetlock extension increased when the horses performed lengthened trot paces, more in extended than medium trot. The loading of the carpus and shoulder were related to fetlock extension, suggesting that lengthened paces affect the loading of the entire forelimb. Lengthened paces may be contraindicated in horses with fetlock hyperextension or

suspensory ligament injury; they may be a potential risk factor for these injuries. Interaction with the surface could also have a role that could be further investigated.

Ethical animal research: The study was approved by the Animal Health Trust ethical review committee. Owners gave informed consent for their horses' inclusion in the study. Sources of funding: Elise Pilkington Charitable Trust, Dr Wilfrid Bechtolsheimer, British Dressage. Competing interests: None declared.

IDENTIFICATION OF DISEASE SPECIFIC METABOLIC FINGERPRINTS IN EARLY OSTEOARTHRITIS

tPeffers, M., *Riggs, C., §Phelan, M. and tClegg, P.

institute of Ageing and Chronic Disease, University of Liverpool,

Liverpool, L693GA, UK; *Hong Kong Jockey Club, Hong Kong; §NMR

Centre, University of Liverpool, Liverpool, L69 7ZB, UK.

Email: peffs@liv.ac.uk

Reasons for performing study: Synovial fluid (SF) is located in joint cavities, tendon sheaths and bursae. In joints it comprises a serum filtrate with additional contributions from articular cartilage, synovium and bone. Low molecular weight metabolites represent the end product of the cell regulatory processes. Synovial fluid represents a potential source of disease specific metabolites that could aid in the understanding of the pathogenesis of osteoarthritis (OA) and be used in its early diagnosis.

Objectives: We hypothesise that there are different metabolomic profiles that can be identified in early OA SF and some of these metabolites are potential biomarkers.

Study design: Cross-sectional study.

Methods: Synovial fluid was used from the metacarpophalangeal joints of 9 normal and 9 OA Thoroughbred horses following macroscopic, microscopic and synovitis scoring. SF was analysed with Proton (1H)-nuclear magnetic resonance (NMR) spectroscopy with a 600 MHz Avance III equipped with a cryoprobe and chilled sample-jet autosampler. The software we use is Topsin 3.1 and IconNMR 4.6.7. The following methods were used in order to identify changes in lipids and small molecules; 1D Nuclear Overhauser Effect, Longitudinal Encode-decode and Carr-Purcell-Meiboom-Gill. Data analysis was undertaken using unsupervised statistical methods and Ingenuity Pathway Analysis (IPA).

Results: The results demonstrated clustering on principle component analysis between normal and OA samples. Seven metabolites were identified as significantly different in OA P<0.05; mobile lipid 1, methyl group, 2 lactates, proline and 2 citrates. Furthermore total lipid load correlated very closely to Mankin's scoring. Using IPA we identified metabolic pathways relating to altered glycolysis in early OA.

Conclusions: We identified the metabolic fingerprint of early OA which may allow for better phenotyping of disease states and thereby facilitate targeting of improved treatment regimes.

Ethical animal research: Samples were collected at post mortem examination with informed owner consent. Sources of funding: Wellcome Trust and the MRC and Arthritis Research UK as part of the MRC -Arthritis Research UK Centre for Integrated research into Musculoskeletal Ageing (CIMA). Competing interests: None declared.

NORMAL RADIOGRAPHIC ANATOMY OF THE DONKEY FOOT FROM BIRTH TO 2 YEARS OF AGE

t*Van Thielen, B., §Pestieau, P., #Van DerStrieckt, A., ^Willekens, I., §Busoni, V., *Verhelle, F., *Goossens, P., ttDelperdange, P., #De Mol, G., ^Jacqmot, O., *Buls, N., *Kichou, M. and t#de Mey, J. MOVE- HIM (Morpho Veterinary & Human Imaging) Brussels, UZBrussel; *Department of Radiology - UZ Brussel; §Faculté de la Médecine Vétérinaire, Université de Liège; #EHSAL - HUB, Brussels; ffNaturane SA, Bastogne, Belgium. Email: lafourbure@free.fr

Reasons for performing study: Normal radiographic anatomy of the juvenile donkey foot has not been reported previously.

Objectives: To provide a radiographic survey of the anatomical development of the donkey foot from 0 to 2 years of age.

Study design: Radiographic survey.

Methods: The right front foot of 9 donkey foals born in the spring of 2012, housed and fed in the same conditions, were radiographed every month for the first 6 months of age and every 3 months for the following 18 months. Latero-medial radiographs with and without barium markers at the coronary band and anterior-posterior radiographs of both front feet were obtained during weightbearing. Radiographs were obtained at 55 kV and 3 mAs with mobile x-ray equipment (Gierth RHF 200 ML, Examion DR810).

Results: The distal physis of the metacarpus (McIII) was closed at the mean age of 17.8 months (SD: 11.5, 21). The proximal physis of the proximal phalanx was closed at the mean age of 15.5 months (SD: 11.5, 21). The distal physis appeared as a clear radiolucent line at 2 weeks of age and was still visible subtly at 24 months. The proximal physis of the middle phalanx was closed at the mean age of 10.7 months (SD: 11.5, 19). The distal physis was visible at birth but closed at 4 days.

Conclusions: Based on our results, it seems that physes close at an older age in the donkeyfoal than in the horse.

Ethical animal research: The study was approved by the Ethics committee of the Vrije Universiteit Brussel (VUB), Brussels, Belgium. (VUB/14-272-2). Owners gave informed consent for their horses' inclusion in the study. Source of funding: The authors acknowledge Vtrade Belgium forthe logistic assistance. Competing interests: None declared.

EFFECTS OF TIME OF DAY, AMBIENT TEMPERATURE AND RELATIVE HUMIDITY ON THE REPEATABILITY OF INFRARED THERMOGRAPHIC IMAGING IN HORSES

Satchell, G., McGrath, M., Dixon, J., Pfau, T. and Weller, R. Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK.

Email: rweller@rvc.ac.uk

Reasons for performing study: Infrared imaging is becoming popular as an aid to traditional diagnostic tools, its repeatability under practically relevant conditions is still discussed.

Objectives: We hypothesise that time of day, ambient temperature and relative humidity affect thermography readings, and that there is no difference between values from left and right side.

Study design: Repeated thermography in a convenience sample.

Methods: Fifteen sound horses were thermographically imaged at3 time points in the same day (08.00, 12.00 and 16.00 h). Images were taken of the following regions: neck, carpus, distolateral thoracic limbs (cranial and tendon areas), thoracolumbar, pelvis, hock and pelvic limb tendons. Relative humidity and ambient temperature were recorded for each session.

Results: There was a significant difference between the temperature readings during the 3 imaging sessions in all areas (Friedman and Kruskal-Wallis; all P<0.014). Ambient temperature and relative humidity correlated with thermography readings in the caudal imaging areas (P<0.008 [temperature], P<0.032 [humidity]) of the horses, with an exception of one hock reading, but not in all cranial areas (P<0.365 [temperature], P<0.992 [humidity]) (Spearman's Rho). All but 2 regions (minimum values in the carpus and thoracic tendon areas in the morning session, (P = 0.033,0.034) did not show significant difference between left and right sides at the same time of day (all P>0.057).

Conclusions: Time of day, ambient temperature and relative humidity must be considered when using infrared imaging. Variations between the left and right sides of the horse can occur and should be considered during the analysis of pathological asymmetry.

Ethical animal research: Ethical approval was granted from the Royal Veterinary College Ethics and Welfare committee as part of the first and second author's final year research project. Source of funding: Funding was provided by the Royal Veterinary College as part of the first and second authors' final year research project. Competing interests: None declared.

SENSITIVITY OF TRANSCRANIAL MAGNETIC STIMULATION IN RELATION TO HISTOPATHOLOGICAL FINDINGS IN SIX HORSES WITH COMPRESSIVE LESIONS OF THE SPINAL CORD

tyanschandevijl, K., *Nollet, H., §Vercauteren, G., 'Ducatelle, R. and 'Deprez, P.

fEquine Hospital De Bosdreef, Moerbeke-Waas, Belgium; *Dierenartsenpraktijk Westhove, Belgium; §Diagnostic Lab Zoolyx, Belgium; #Faculty of Veterinary Medicine, Ghent University, Belgium. Email: katleen.vanschandevijl@bosdreef.be

Reasons for performing study: Transcranial magnetic stimulation (TMS) is an electrophysiological technique used to elicit motorevoked potentials (MMEPs) to evaluate the functional integrity of the descending motorfibres in the spinal cord. Successful application of the technique was reported in horses with spinal cord compression. However, limited data are available on the correlation of TMS with histopathological changes.

Objectives: To determine sensitivity of TMS for assessing the integrity of the spinal cord in horses with compressive lesions of the spinal cord.

Study design: Case series.

Methods: The study was conducted on 6 horses with spinal ataxia grade III-V/V admitted to the Faculty of Veterinary Medicine, Ghent University. The horses underwent TMS, radiography of the cervical or thoracolumbar vertebral column, and myelography (4/6). All horses were subjected to euthanasia and the spinal cord examined histopathologically.

Results: In 5/6 horses MMEPs with abnormal onset latencies in both extensor carpi radialis muscles and cranial tibialis muscles were recorded, suggesting a cervical spinal cord lesion. Radiography revealed cervical vertebral malformation (4/5) with cervical vertebral canal stenosis (3/5) and tumour/osteomyelitis (1/5). In 1/6 horse MMEPs with normal onset latencies in extensor carpi radialis muscles and prolonged onset latencies in tibialis cranialis muscles were recorded, suggesting a

thoracolumbar spinal cord lesion. Radiography revealed deformation of the 7th and 8th thoracic vertebrae. Myelography showed reduction in dural diameter and dorsal contrast column (4/4). Histopathological examination of the spinal cord confirmed compressive type lesions in all 6 horses with degenerative changes in the white matter of all funiculi, ballooning of myelin sheets, swollen axons, loss of axons and astroglial activation.

Conclusions: In this case series abnormal function of descending motor pathways as registered by TMS showed 100% sensitivity with the histopathological characteristics of compressive lesions in the spinal cord, but the number of horses is limited and further research is warranted.

Ethical animal research: Research ethics committee oversight not currently required by this conference: the study was performed on material collected during clinical procedures. Explicit owner informed consent for participation in this study was not stated. Source of funding: Not applicable. Competing interests: None declared.

DIFFUSION OF RADIODENSE CONTRAST MEDIUM AFTER PERINEURAL INJECTION OF THE PALMAR DIGITAL NERVES

+Nagy, A. and *Malton, R.

fOld Town, Dubai, United Arab Emirates; *Dubai Stable Veterinary Clinic, Dubai, United Arab Emirates. Email: annamaria.nagy@yahoo.com

Reasons for performing study: Limited information exists on distribution of local anaesthetic solution following palmar digital nerve blocks.

Objectives: To demonstrate potential distribution of local anaesthetic solution following perineural injection of the palmar digital nerves using 2 different volumes of contrast medium and 2 different injection sites.

Study design: Experimental.

Methods: Twelve mature horses were used. Perineural injection of the palmar digital nerves were performed at the level of or 2 cm proximal to the proximal aspect of the ipsilateral ungularcartilage, using 1.5 or2.5 ml radiodense contrast medium. In total 96 injections were performed. Four standard radiographic views of the pastern were obtained immediately after injections and 10 and 20 min later. Images were analysed subjectively and objectively.

Results: After distal injections, the contrast medium was more localised around the injection site; after proximal injections the contrast patch had greater proximal-distal length. The greatest proximal diffusion was to 31.7% of the length of the proximal phalanx (from distal) after distal injections and to 70% after proximal injections. The larger volume resulted in significantly greater proximal diffusion than the smaller volume at the distal, but not at the proximal injection site (P<0.01). There was significant proximal diffusion with time after proximal and distal injections (P<0.01). In most limbs numerous radiopaque lines of various thickness extended proximally from the contrast patches; subjectively, their number and thickness were greater at the distal injection site.

Conclusions: Palmar digital nerve blocks at the level of the ungular cartilage using <2.5 ml local anaesthetic solution may improve proximal interphalangeal joint and pastern region pain. If using a more proximal site, distal fetlock region pain may be improved. Due to diffusion into lymphatic vessels, too small a volume at the distal injection site may not provide sufficient analgesia.

Ethical animal research: Written consent had been obtained from a representative of the horses' owner prior to starting the study. Source of funding: None. Competing interests: None declared.

DIFFUSION OF RADIODENSE CONTRAST MEDIUM AFTER A MID-PASTERN RING BLOCK

tMalton, R. and *Nagy, A.

fDubai Stable Veterinary Clinic, Dubai, United Arab Emirates; *Old Town, Dubai, United Arab Emirates. Email: russell.malton@gmail.com

Reasons for performing study: Diffusion of local anaesthetic solution after a mid-pastern ring block has not been investigated.

Objectives: To demonstrate potential distribution of local anaesthetic solution following injection of radiodense contrast medium as performed for a mid-pastern ring block.

Study design: Experimental.

Methods: Twelve mature horses were used. One and a half ml radiodense contrast medium was injected over the medial or lateral palmar digital nerve at the level of the proximal aspect of the ungular cartilages. A dorsal ring block was performed on the ipsilateral side, 1.5 cm proximal to the palpable palmar aspect of the proximal eminence of the middle phalanx, using 2 or 5 ml contrast medium. Both forelimbs were injected on 2 days (48 injections). Four standard radiographic views of the pastern were obtained immediately, 10 and 20 min after injections. Images were analysed subjectively and objectively.

Results: After dorsal injections the contrast medium was distributed in a diffuse patch over the ipsilateral half of the proximal phalanx (PP), extending proximally over the half of the length of PP in all limbs (greatest proximal extension: 89.0% of the length of PP [from distal] after 2 ml, 94.2% after 5 ml). There was significant proximal diffusion in the first 10 min after injection and significant dorsal diffusion between all time points (P<0.01). There was significant positive association between injected volume and the proximal extension of the dorsal contrast patch (P = 0.01). The median dorsal diffusion was to the dorsal midline of PP; 5 ml contrast medium resulted in significantly greater dorsal diffusion than 2 ml (P<0.01). The dorsal and the palmar contrast patches did not merge.

Conclusions: Diffusion to the proximal aspect of P1 occurred even after injection of only 2 ml contrast medium. Fetlock region pain may be influenced by a mid-pastern ring block.

Ethical animal research: Written consent had been obtained from a representative of the horses' owner prior to starting the study. Source of funding: None. Competing interests: None declared.

PROXIMAL SUSPENSORY DESMOPATHY IN HINDLIMBS: A CORRELATIVE CLINICAL, ULTRASONOGRAPHIC, GROSS POST MORTEM AND HISTOLOGICAL STUDY

tDyson, S. and «Pinilla, M.J.

fCentre for Equine Studies and*Centre for Preventative Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, CB8 7UU, UK; §Current address: Finn Pathologists, The Veterinary Laboratory, Hoxne Road, Diss, IP21 5TT, UK. Email: sue.dyson@aht.org.uk

Reasons for performing study: It has been suggested that ultrasonography is unreliable for the detection of hindlimb proximal suspensory desmopathy (PSD) based on comparison between ultrasonographic and magnetic resonance images.

Objectives: To compare ultrasonography with gross and histopathological post mortem examination in horses with PSD diagnosed based on the response to local anaesthesia and ultrasonography.

Study design: Retrospective study.

Methods: Nineteen horses with hindlimb PSD were humanely destroyed. The ultrasonographic abnormalities were graded prospectively as mild, moderate or severe based on predefined criteria. Thirty-seven lame limbs were examined grossly and 36 suspensory ligaments (SLs) were examined histologically. The histological images were graded blindly based on predefined criteria (0-3 for each tissue type; 0 = normal, 3 = severe abnormality). Descriptive statistics were performed.

Results: Ultrasonographic lesions were graded moderate in 31/38 (81.6%) and severe in 7/38 (18.4%) limbs; in 4/36 (11.1%) limbs adhesion formation between the proximal aspect of the SL and the accessory ligament of the deep digitalflexortendon was predicted. Gross post mortem examination revealed substantial adhesions between the proximal aspect of the SL and adjacent soft tissues in 10/37 (27.0%) limbs; in 10/37 (27.0%) limbs there were adhesions between the body of the SL and the mid plantar aspect of the third metatarsal bone, extending distally in 6 (16.2%) limbs. Histology revealed abnormalities (grades 1-3) of the collagenous tissue in 25/36 (69.4%) limbs. Muscle was abnormal (grades 1-3) in 35/36 (97.2%) limbs and adipose tissue (grades 1-3) in 16/36 (44.4%) limbs. Neural abnormalities (grades 1-3) were seen in 23/36 (63.9%) limbs and vascularchanges (grade 1 and 2) in 2/36 (5.6%) limbs. In 1/36 limbs no abnormality was detected.

Conclusions: Ultrasonography was reasonably reliable for the detection of SL pathology based on histology as a gold standard, but the ability to detect gross adhesions was limited.

Ethical animal research: The study was approved by the Ethical Review Committee of the Animal Health Trust and had informed consent of the owners. Source of funding: None. Competing interests: None declared.

AN EPIDEMIOLOGICAL INVESTIGATION OF THE AID OF MAGNETIC RESONANCE IMAGING IN DETERMINING LONG-TERM PROGNOSIS FOR SOUNDNESS FOLLOWING PALMAR/PLANTAR DIGITAL NEURECTOMY FOR CHRONIC FOOT PAIN

Wylie, C.E., Payne, R.J., Bathe, A.P., Greet, T.R.C., Head, M.J., Boys-Smith, S.J. and Powell, S.E.

Rossdales Equine Hospital, Cotton End Road, Exning, Newmarket, Suffolk, CB8 7NN, UK.

Email: claire.wylie@rossdales.com

Reasons for performing study: Accurate diagnosis of chronic foot pain by magnetic resonance imaging (MRI) allows appropriate case selection for palmar/plantar digital neurectomy (PDN).

Objectives: To report follow-up for chronic foot pain treated by PDN, with and without MRI diagnosis.

Study design: Retrospective cohort study.

Methods: The electronic patient records of all animals that underwent PDN were reviewed. Follow-up was obtained from owners using a structured postal/telephone questionnaire. Chi squared/Fisher's exact tests or 2-sample t tests were used, with statistical significance set as P<0.05.

Results: One hundred and nine PDN cases were undertaken. Follow-up response rate was 72.5%. From these 79 cases, 52 had MRI (MRI+) and 27 did not (MRI-). There was no significant difference in case distribution between the 2 groups: predominantly horses, Warmbloods, geldings, used

for full competitions, except MRI+ were younger than MRI- (median 9.99 and 11.71 years respectively, P = 0.004). Median follow-up time for MRI+ was 31.4 months, and for MRI- was 36.8 months. There was no significant difference in outcome. In total, 78.9% MRI+ achieved their intended use, compared with 73.1% MRI-. For those intended for exercise, 83.7% MRI+ reached a level of exercise, compared with 87.5% MRI-. Median length of exercise maintenance was 25.2 months for MRI+ and 24.0 months for MRI-. For MRI+there was one suspected and one confirmed neuroma and 4 neuritis cases. Two MRI- animals developed neuritis. Complications requiring euthanasia occurred in 2 MRI- cases: complete rupture of the deep digitalflexortendon in a bilateral forelimb lameness and one previous chronic laminitic with solar prolapse.

Conclusions: These results are comparable with previous reports of 80% of MRI+ returning to previous athletic use for 20 months. Achievement of intended use, length of exercise maintenance and complication rate was similar with and without MRI diagnosis, although both catastrophic complications occurred in animals which did not undergo MRI.

Ethical animal research: Ethical approval obtained: AHT47-2013. Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: C.E. Wylie is funded by The Margaret Giffen Charitable Trust. Competing interests: None declared.

THE USE OF ELECTROMYOGRAPHY INCLUDING INTERFERENCE PATTERN ANALYSIS TO DETERMINE MUSCLE FORCE OF THE DEEP DIGITAL FLEXOR MUSCLE IN CASE OF EQUINE LAMINITIS

^Hardeman, L.C., Van der Meij, B.R., t§Back, W., «Van der Kolk, J.H. and tWIjnberg, I.D.

department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114,3584 CM Utrecht, The Netherlands; *De Klomp Veterinarians, De Klomp 4, 6745 WB De Klomp, The Netherlands; §Department of Surgery and Anaesthesiology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium; #Euregio Laboratory Services, Section Equine Metabolic and Genetic Diseases, Stadionplein 46, 6225 XW Maastricht, The Netherlands; ffDivision of Clinical Veterinary Medicine, Swiss Institute for Equine Medicine, Vetsuisse Faculty, University of Bern and Agroscope, Bern, Switzerland.

Email: l.c.hardeman@uu.nl

Reasons for performing study: In cases of laminitis, an increased muscle force or contracture of the deep digital flexor muscle (DDFM) is suggested, but evidence-based research is lacking.

Objectives: To test if the DDFM of laminitic equines shows an increased muscle force detectable by needle-EMG including Interference Pattern Analysis (IPA).

Study design: Cross-sectional study.

Methods: Three groups consisted of Group 0 (control): 6 Royal Dutch Sport horses, 3 Shetland ponies and one Welsh pony (healthy, sound adults, mean ± s.d. weight 411 ± 217 kg). Group 1: 3 Royal Dutch Sport horses, one Friesian, one Haflinger, one Icelandic horse, 2 Welsh ponies, one miniature Appaloosa and 6 Shetland ponies (adults, mean ± s.d. weight 310 ± 172 kg) suffering from acute or chronic laminitis. EMG measurements including firing frequency (F) and IPA parameters Turns/Second (T), Amplitude/Turn (M) and Ratio M/T (R) were performed. ANOVA was used to analyse data. P values of P<0.05 were considered significant.

Results: Mean ± s.d. F of Group 0 and Group 1 was 53 ± 11 and 72 ± 21 Hz, mean ± s.d. T was 112 ± 57 and 106 ± 42, mean ± s.d. M was 284 ± 51 and 254 ± 38 |V and mean ± s.d. R was 0.39 ± 0.17 and

0.42.± 0.16%, respectively. The firing frequency of Group 1 was significantly higher compared to Group 0 (P = 0.02), whereas other differences were not significant.

Conclusions: In human medicine, an increased firing frequency is a characteristic of increased muscle force [1,2]. Thus, the increased firing frequency of the DDFM in case of laminitis suggests an elevated muscle force. As all parameters show a high variance, a repeated study including a largertest group is advised.

Ethical animal research: Data collection from controls was approved by the Animal Welfare Committee of Utrecht University, approval number 2008.III.07.061 and 2013.III.01.012. Clinical cases were privately owned and written owner consent was obtained. Source of funding: None. Competing interests: None declared.

References

1. Finsterer, J. (2001) EMG-interference pattern analysis. J. Electromyogr. Kinesiology 11, 231-246.

2. Sanders, D.B., Stalberg, E.V. and Nandedkar, S.D. (1996) Analysis of the electromyographic interference pattern. J. Clin. Neurophysiol. 13,385-400.

A RETROSPECTIVE STUDY OF SAGITTAL PLANE SLAB FRACTURES OF THE THIRD CARPAL BONE IN RACING THOROUGHBRED HORSES

Tallón, R.E. and Bladon, B.M.

Donnington Grove Veterinary Surgery, Newbury, Berkshire, RG14 2JB, UK. Email: rosetallon@donnlngtongrove.com

Reasons for performing study: Sagittal plane slab fractures of the third carpal bone are a recognised injury in the racehorse. One study [1] reported 32 horses with sagittal fractures, 69% raced again. Surgical management appeared beneficial, with all horses that underwent inter-fragmentary compression racing again.

Objectives: To document the success rate following sagittal slab fracture of the third carpal bone in UK-based racehorses, and to compare conservative and surgical management.

Study design: Retrospective study.

Methods: Inclusion criteria were Thoroughbred racehorses with a simple sagittal slab fracture of the third carpal bone. Exclusion criteria were comminuted fractures, radial carpal bone fractures and short incomplete linear lucencies. Fractures were classified as complete, incomplete or uncertain. Time from injury to next race was recorded. Success rates were compared by Fisher's exact test.

Results: Forty horses were identified. Two were subjected to euthanasia and 3 have <6 months follow-up. Eleven were managed nonsurgically of which 4 (36%) were complete (5 uncertain) and 7 (64%) raced, 154-508 days following injury (median 242 days). Twenty-seven horses underwent surgery to place a single 3.5 mm (n = 26) or 4.5 mm (n = 1) lag screw under arthroscopic guidance, of which 18 (67%) were complete. Thirteen (48%) raced again 147-711 days following surgery (median 256 days) P = 0.48. Of 23 horses with complete fractures 13 (57%) raced again, compared with 5/15 (33%) horses with incomplete fractures P = 0.2. Of horses with complete fractures, 10/18 (55%) underwent surgery and raced again compared to 3/4 (75%) horses managed conservatively P = 0.62.

Conclusions: The results confirm that the prognosis for athletic function is favourable but do not suggest that surgery is beneficial, or necessary for complete fractures. The numbers managed conservatively are small and it was not clear radiographically if the fracture was complete in 5/11 horses.

Ethical animal research: Research ethics committee oversight not currently required by this conference: retrospective study of clinical

records. Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: None. Competing interests: None declared.

Reference

1. Kraus, B.M., Ross, M.W. and Boston, R.C. (2005) Surgical and nonsurgical management of sagittal slab fractures of the third carpal bone in racehorses: 32 cases (1991-2001). J. Am. Vet. Med. Assoc. 226, 945-950.

PLANT THORN SYNOVITIS CAUSED BY PRUNUS SPINOSA (BLACKTHORN) PENETRATION IN 35 HORSES

Ashton, N.M. and Doles, J.

School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Loughborough, Leicestershire, LE12 5RD, UK. Email: neal.ashton@oakhamvethospital.co.uk

Reasons for performing study: Blackthorn (Prunus spinosus) is recognised as causing infections and tissue reactions.

Objectives: To describe the presentation, diagnosis, treatment and outcome of blackthorn plant thorn synovitis in the horse.

Study design: Case series.

Methods: All cases in this prospective study presented with acute onset synovitis within 24 h of thorn penetration, had a standardised clinical assessment, surgical treatment and aftercare. Surgical treatment was performed within 24 h of presentation under general anaesthesia, using a 2-stage procedure: Stage 1: perisynovial technique. Ultrasound guided placement of a 20 gauge 35 mm needle markerthat is used as a guide for electrosurgical dissection onto perisynovial thorn fragments. Stage 2: endoscopic technique. Using standard and novel portals to locate and remove thorn fragments and debris from synovial structures.

Results: Thirty-five cases metthe study inclusion criteria overa 24 month period. Mean lameness score on presentation was 4/5 (range 1-5). The most commonly affected structures were fetlock joints (11/35) and tendon sheaths (10/35). Mean synovial fluid total protein was 50.5 g/l (range 18-116), and TNCC was 158 x 109 (range 21-412) on presentation and 12 x 109 (range 1-46) at 48 h post operatively. All synovial fluid cultures were negative. All horses were sound (grade 0) at 5 days post operatively and all returned to full work.

Conclusions: There are a limited number of case series of blackthorn injury in humans; however, the consensus is that surgical treatment is required for a successful outcome. The 2-stage surgical procedure described, achieved accurate identification and removal of thorn material in all cases. In contrast to previous studies on synovial sepsis, these cases had a positive outcome despite high pre- and post operative synovial fluid total protein and TNCC. These findings suggest that thorn synovitis cases have a different aetiology from synovitis originating from sepsis or contamination.

Ethical animal research: The study was reviewed and approved by the Ethics Committee, School of Veterinary Medicine and Science, University of Nottingham. Owners gave informed consentfortheirhorses' inclusion in the study. Source of funding: None. Competing interests: None declared.

THE EFFECT OF THREE DIFFERENT SHOEING CONDITIONS ON TENDON STRAIN IN THE THOROUGHBRED FORELIMB

Ault, B., Starling, G., Parkes, R., Pfau, T., Pardoe, C., Day, P., Bettison C. and Weller, R.

Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, UK. Email: bault@rvc.ac.uk

Reasons for performing study: Previous studies show the effect of toe or heel wedges on tendon strain but there is little understanding of the effect of other shoe types.

Objectives: To quantify the effect of different shoeing conditions on the strain in the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), distal check ligament (ALDDFT) and suspensory ligament (SL).

Study design: Controlled experimental study.

Methods: Twelve equine cadaver forelimbs were loaded onto a force plate mimicking stance phase. Markers were placed proximally and distally in each tendon structure and tracked using a motion capture system and strain was calculated. Tendon strain was determined for the following conditions: barefoot, glue on heart bar and aluminium racing plates with and without packing material. Data were analysed using a mixed effects model.

Results: Significant variation in strain was observed between tendons. The DDFT had the lowest strain, then the ALDDFT, SDFT and SL. Glue on heart bar shoes significantly increased SDFT and SL strain compared to barefoot for the same leg force. Aluminium racing plates without packing material increased ALDDFT and SDFT strain and with packing material increased ALDDFT and SL.

Conclusions: Shoe selection should be based on minimising strain in the tendon with greatest injury risk. Aluminium racing plates with packing material maybe most appropriate forthe majority of racehorses as they do not significantly increase SDFT strain.

Ethical animal research: Research ethics committee oversight not currently required by this conference: the study was performed on material obtained from an abattoir. Source of funding: The authors would like to thank the Horserace Betting Levy Board for their support of this project. Competing interests: None declared. Acknowledgements: We thank Peter Day, Carl Bettison, Chris Pardoe, Marianna Biggi and Emily Sparkes.

OUTCOME AND OWNER PERCEPTION OF CONSERVATIVE AND SURGICAL MANAGEMENT OF FRACTURE OF THE ULNA IN 20 HORSES

Ladefoged, S., Wallin, J., Toth, T. and Andersen, P.H.

Equine Clinic, Department of Clinical Sciences, Swedish University of

Agricultural Sciences, Uppsala, Sweden.

Email: soren.ladefoged@uds.slu.se

Reasons for performing study: While open reduction and internal fixation is the treatment of choice for most ulnar fractures conservative treatment is sometimes chosen due to financial constraints. Additional motives for the choice of treatment may be present, and the clients perception is therefore of interest.

Objectives: To compare survival and outcome between horses treated for an ulnar fracture, either surgically or conservatively and to assess clients perception of treatment.

Study design: Retrospective study.

Methods: Medical records and radiographs of horses treated between January2002 and December2012, with a diagnosis of ulnarfracture were reviewed. Information regarding short- (within 1 year) and long-term (>1 year) outcome and owner satisfaction with treatment was obtained via telephone questionnaires. Differences between groups were investigated using a chi-square or Fisher's exact test.

Results: Fracture types included 11 type 4, 7 type 5, one type 2, and one type 1b fracture. Eleven horses were treated surgically (Group 1). Nine horses were managed conservatively (Group 2). Group 1: 7/11 (64%) survived >1 year, 5/11 (45%) returned to previous athletic level. In Group 2: 6/9 (67%) survived >1 year, 4/9 (43%) returned to previous athletic level. No significant difference in outcome could be detected. There was no difference in the total treatment cost for horses that stayed at the hospital (P = 0.22). Owners in Group 1 expressed more satisfaction with the treatmentthan owners in Group 2. Several ofthe latter expressed welfare concerns regarding the prolonged stall confinement in harness involved with this treatment.

Conclusions: Veterinarians recommending therapy for cases of ulnar fractures should be aware that many can be treated surgically with a good outcome. Prolonged hospitalisation and stall confinement of horses treated conservatively was a major welfare concern of the owners interviewed and had the same total cost as surgical treatment.

Ethical animal research: Ethical review not currently required by this conference: retrospective clinical study. Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: None. Competing interests: None declared.

A PRELIMINARY STUDY OF THE EFFECT OF MANUAL CHIROPRACTIC TREATMENT ON THE SPLENIUS MUSCLE IN HORSES WHEN MEASURED BY SURFACE ELECTROMYOGRAPHY

+Langstone, J., *Ellis, J. and +Cunliffe, C.

fMcTimoney College of Chiropractic, Abingdon, OX14 1BZ, UK;

Warwickshire College, Moreton Morrell Centre, Warwickshire, CV35 9BL,

Email: office@kismettherapy.co.uk

Reasons for performing study: A quantifiable measure of muscle activity related to the cervical spine may provide further understanding and evidence based support for chiropractic techniques. Surface electromyography (sEMG) is a noninvasive method of measuring muscle activity ofthe splenius muscle when the horse is at rest.

Objectives: To determine if there is a relationship between objective measurable muscle parameters and misalignments and muscle tension in the equine cervical spine.

Study design: Controlled paired randomised study.

Methods: Privately owned horses (n = 14), of mixed sex, age and mean height 157.8 cm were selected and assigned a group by matching work, management regime, age, sex and breed. The treatment group (n = 7) underwent manual chiropractic treatment following palpation. The control group underwent palpation only. A Delsys 4 sensor system was used for data collection. Probes were positioned on the muscle halfway between C1/C2 joint and the crest on the left and right sides, between the tendon insertion and the motor point to maximise signals. sEMG readings were taken at immediately before (0) and after palpation (PP) and 30 min later

(30). Data were tested for normality and variance by one-way ANOVA and paired ttest.

Results: Post treatment, there was a significant decrease (P<0.01) in sEMG activity for treatment group at 0 to 30 and PP to 30. There was a significant decrease (P<0.05) in sEMG for right side for treatment group at 0 to 30 and PP to 30. There were no such significant effects for the control group. The majority (83%) of horses had atlas rotation and tilt to the right.

Conclusions: This preliminary study supports use of sEMG as a means of assessing muscle activity of equines and suggests a statistically significant reduction in splenius muscle activity is observed following manual chiropractic treatment although the benefit to the horse is unknown.

Ethical animal research: The study protocol was reviewed by the College Research Ethics Committee before commencement ofthe study. Owners gave informed consent for their horses' inclusion in the study. Source of funding: McTimoney College of Chiropractic assisted with the hiring ofthe equipment. Competing interests: None declared.

A COMPARISON OF A 4% MODIFIED FLUID GELATIN AND A 6% HYDROXYETHYL STARCH ON HAEMODILUTION, COLLOID OSMOTIC PRESSURE, HAEMOSTASIS AND RENAL PARAMETERS IN HEALTHY PONIES

Gratwick, Z., Viljoen, A., Page, P.C., Goddard, A., Fosgate, G.T. and Lyle, C.H.

Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, South Africa. Email: zoe-ford@live.co.uk

Reasons for performing study: Adverse effects on renal health and haemostasis have been documented in human patients administered hydroxyethyl starches (HES). Gelatins could provide useful substitutes for HES should similar adverse effects be identified in horses.

Objectives: To compare the effects of a 4% modified fluid gelatin (MFG) with a 130/0.4 6% tetrastarch (TES) on haemodilution, colloid osmotic pressure (COP), haemostasis and renal parameters in healthy ponies.

Study design: Randomised crossover.

Methods: Three treatments (A = 10 ml/kg bwt TES, B = 10 ml/kg bwt MFG and C = 20 ml/kg bwt MFG) were administered to 6 healthy ponies with a one-week washout period. Packed cell volume (PCV), total serum protein (TSP), COP, platelet count, fibrinogen, prothrombin time (PT), activated partial thromboplastin time (aPTT) and thromboelastography (TEG) were measured at baseline and at multiple time points up to 24 h post infusion. Serum creatinine, urine specific gravity (USG), urine protein:creatinine (UPC), urine GGT:creatinine (UGC) and urine sediment examination (USE) were performed before and 24 h after each treatment, and one week after the final treatment.

Results: All treatments caused significant haemodilution and increases in COP with treatment C having a significantly greater effect on PCV than other treatments. The platelet count decreased with all treatments and was significantly lower for treatment C compared with treatment B. No significant differences were observed in any TEG parameter within or between treatments. No significant differences in PT, aPTT or fibrinogen were observed between treatments. Serum creatinine, UGC and UPC did not change significantly pre- and post study. USG and USE remained within normal limits.

Conclusions: 4% MFG could be considered as an alternative to 130/0.4 6% TES for volume expansion and oncotic support. Neither MFG nor TES were associated with clinically significant adverse effects on haemostasis or renal parameters.

Ethical animal research: This research was approved by the University of Pretoria's Animal Ethics Committee. The animals used in the study were part of a research herd belonging to The University of Pretoria. Sources of funding: The Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, The Abe Bailey Trust Fund, The South African Veterinary Foundation and The South African Equine Veterinary Association. Competing interests: None declared.

YELLOW FAT DISEASE (STEATITIS): DESCRIPTION OF 20 CASES WITH EMPHASIS ON TYPICAL ULTRASONOGRAPHIC FINDINGS

van Loon, G. Lefere, L., Bauwens, C., Kleyn, K., Broux, B., De Clercq, D. and Deprez, P.

Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. Email: gunther.vanloon@ugent.be

Reasons for performing the study: Yellow fat disease or steatitis is characterised by a local or general inflammation of fat tissue and is occasionallyfound in horses. Diagnosis is challenging because of the wide range ofnonspecific clinical signs.

Objectives: To describe clinical signs, treatment, outcome and ultrasonographic findings in horses with steatitis.

Study design: Retrospective study (January 2008 to January 2015).

Methods: History, clinical signs, ultrasonographic findings, diagnosis, treatment and outcome were recorded.

Results: Twenty cases (18 horses, 2 donkeys; 9 mares, 9 stallions, 2 geldings) were retrieved from 13,707 patient records. Mean age was 1.6 (± 0.8) years (range 1 month-3.5 years). All cases appeared between October and February except for one (August). History included dullness, recumbency, decreased appetite and weight loss. Fever, ventral oedema, stiff/painful gait and painful neck were found. Lowhaematocrit, low vitamin E and selenium and increased levels of creatinine kinase and particularly lactate dehydrogenase were almost consistent findings. On ultrasound, ventral oedema was found. Subperitoneal, perirenal, mesenteric, coronary and caudal mediastinal fat showed homogenously increased echogenicity. Especially the subperitoneal fat was surrounded by oedema or free fluid. Increased amounts of abdominal, thoracic and pericardial fluid were often found. Fat biopsies were taken in the neck or from the retroperitoneal fat in the ventral flank. In all horses where fat biopsy was taken (n = 13), steatitis was confirmed. Treatment consisted of selenium and vitamin E (intra-muscular injection followed by oral treatment) supplementation and anti-inflammatory treatment (dexamethasone or prednisolone parenteral or oral) for at least 1-4 weeks. Fourteen animals (70%) survived. Full recovery took about 2-6 months.

Conclusions: Yellow fat disease may be underdiagnosed because of the nonspecific clinical signs. Ultrasound was extremely helpful for making a diagnosis. Recovery was rather slow but was achieved in 70% of the animals.

Ethical animal research: Research ethics committee oversight not currently required by this conference: retrospective study of clinical records. Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: Ghent University (institutional). Competing interests: None declared.

ACCURACY AND COMPLICATION RATES OF MAXILLARY NERVE BLOCKS: A COMPARISON OF TECHNIQUES USING SURFACE LANDMARKS, ULTRASOUND AND GPS-GUIDANCE

Cordner, B., Dixon, J. and Witte, T.

Department of Clinical Sciences and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, UK. Email: bcordner@rvc.ac.uk

Reasons for performing study: Perineural analgesia of the equine maxillary nerve is used for diagnostic and surgical procedures. Little data exists to evaluate accuracy and complication rates with current techniques.

Objectives: This study compared 2 previously described approaches to maxillary nerve analgesia, and a novel needle guidance positioning system (SonixGPS™, Ultrasonix Medical Corporation, Richmond, British Columbia, Canada), assessing relative accuracy and complication rates of each method when performed by inexperienced operators.

Study design: Cadaver study.

Methods: Clinical veterinary students performed surface landmark, ultrasound and GPS guided contrast injections, to simulate maxillary nerve blocks in 38 equine cadaver heads. Computed tomography was then used to assess accuracy (successful deposition of contrast in contact with the maxillary nerve), and complication rate (contrast identified within surrounding vasculature or periocular structures), associated with each method.

Results: Perineural injection of contrast around the maxillary nerve was attempted 76 times, with an overall success rate of 65.8% (50/76), and complication rate of 53.9% (41/76). Success rates were 50% (13/26) with surface landmark, 65.4% (17/26) with ultrasound and 83.3% (20/24) with GPS guided approaches (Fisher's exact P = 0.046). No significant difference in complication rate was found between the 3 methods.

Conclusions: Ultrasound guided maxillary nerve blocks are significantly more accurate than surface landmark approaches when performed by inexperienced operators, and best success rates are achieved with GPS needle guidance. All 3 methods were equivalent in terms of complication rates when performed in cadavers.

Ethical animal research: This study was authorised by the Ethics and Welfare Committee of the Royal Veterinary College. The study was performed on material obtained from abattoirs. Source of funding: Royal Veterinary College. Competing interests: None declared. Acknowledgements: We thank the technical teams of the Equine Referral Hospital Diagnostic Imaging and Pathology departments and the clinical veterinary students.

ANTIMICROBIAL RESISTANCE OF AEROBIC RESPIRATORY ISOLATES FROM YOUNG NEW ZEALAND HORSES

+Toombs-Ruane, L.J., +Riley, C.B., +*Rosanowski, S.M., +§Kendall, A.T. and +Benschop, J.

fInstitute of Veterinary and Biomedical Sciences, Massey University, Palmerston North 4442, New Zealand; *Royal Veterinary College, University of London, London, NW1 0TU, UK; sMalaren Equine Clinic, Sigtuna, Sweden.

Email: l.j.toombs-ruane@massey.ac.nz

Reasons for performing study: Decreased efficacy of veterinary antimicrobials and increased prevalence of multi-drug resistance (MDR) is of concern, but little is known of antimicrobial resistance encompassing the New Zealand (NZ) equine population. Recent concerns have arisen over the emergence of multi-resistant bacteria [1], especially on NZ stud farms where antibiotics are frequently used for respiratory disease without veterinary input [2].

Objectives: To describe bacterial culture and antimicrobial sensitivity results from respiratory samples submitted of young horses (4 weeks to 3 years old).

Study design: Retrospective study of clinical pathology records.

Methods: A database search for isolates and sensitivity of respiratory samples from young horses (April 2004-July 2014) was conducted. The results of in vitro sensitivity testing by Kirby-Bauer disk diffusion were tabulated for major bacterial species isolated. Multiple correspondence analysis was used to describe clustering of multi-drug resistance (MDR) and selected demographic variables.

Results: 237/289 eligible respiratory samples had at least one aerobic bacterial isolate. Most ofthe 774 bacterial isolates were Gram-positive (68%). Streptococcus species were the most common genus isolated (40% of isolates). Sensitivity of Streptococcus spp. to penicillin, gentamicin and ceftiofur was >85%, but only 53% to trimethoprim-sulfamethoxone. Gram-negative sensitivity to ceftiofur, tetracycline, and trimethoprim-sulfamethoxone was <75%. MDR was found for 16% of isolates and in 39% ofhorses.

Conclusions: Penicillin is an appropriate first-line antimicrobial for use in most NZ young horses with suspected bacterial respiratory infection. However, based on findings of MDR, submission of samples for culture and monitoring of sensitivity should be used to inform antimicrobial selection.

Ethical animal research: Not applicable. Sources of funding: Massey University McGeorge Fund; New Zealand Equine Research Foundation. Competing interests: None declared.

References

1. Herdan, C.L., Acke, E., Dicken, M., Archer, R.M., Forsyth, S.F., Gee, E.K. and Pauwels, F.E. (2012) Multi-drug-resistant Enterococcus spp. as a cause of non-responsive septic synovitis in three horses. N. Z. Vet. J. 60,297-304.

2. Rosanowski,S.M., Cogger, N., Rogers, C.W. andBolwell, C.F. (2014) Prevalence and risk factors for respiratory disease on Thorougbred and Standardbred stud farms in New Zealand. Proc. N.Z. Soc. Anim. Prod. 74,5-10.

DEVELOPMENT AND EVALUATION OF A MOLECULAR DIAGNOSTIC METHOD TO RAPIDLY DETECT HISTOPLASMA CAPSULATUM VAR. FARCIMINOSUM (CAUSING EPIZOOTIC LYMPHANGITIS) FROM EQUINE CLINICAL SAMPLES

+Scantlebury, C.E., +Pinchbeck, G.L., *Loughnane, P., §Ashine, T., §Aklilu, N., •Stringer, A.P., ^Gordon, L., +Christley, R.M. and ^McCarthy, A.J. fDepartment of Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Leahurst Campus, Neston, Wirral, CH64 7TE, UK; Microbiology Research Group, Institute of Integrative Biology, Biosciences Building, University of Liverpool, L69 7ZB, UK; sSPANA Ethiopia, College of Veterinary Medicine and Agriculture, Addis Ababa University, DebreZeit campus, PO Box 34, Ethiopia; #SPANA UK, 14 John Street, London, WC1N2EB, UK. Email: claire.scantlebury@liverpool.ac.uk

Reasons for performing study: Histoplasma capsulatum var. farciminosum (HCF), causing epizootic lymphangitis (EZL), is endemic in parts of Africa including, Ethiopia, Senegal and Gambia. Despite its high prevalence, impact on animal welfare and socio-economic importance, there is little evidence upon which to build practical disease control strategies. The performance and availability of diagnostic tests currently used by clinicians is problematic. Methods such as pattern recognition of clinical signs and microscopy lack specificity and other reported methods are either not commercially available or not readily feasible in these settings (e.g. culture). This is a significant barrier to further understanding this disease within endemic countries.

Objectives: To validate a nested PCR method to confirm the presence of HCF in equine clinical samples.

Study design: Cross-sectional.

Methods: Twenty-nine horses with suspected EZL were included from topographically varied regions of Ethiopia. Clinical data, lesion location drawn onto equine silhouettes, blood samples and aspirates of pus from cutaneous nodules were obtained before treatment provided by SPANA clinic. Blood and clinical data were collected from a further 20 horses with no cutaneous EZL lesions. Giemsa stained impression smears of pus were examined microscopically. Aliquots of heat-inactivated pus and blood were inoculated onto Whatman FTA cards and imported to the UK with Defra approved licensing. A nested PCR targeting the ITS region, was used to identify samples containing HCF and PCR products were sequenced.

Results: HCF was confirmed in heat-inactivated FTA card pus samples from 24 horses, additionally, 23 blood samples were positive from EZL suspected cases. Bioinfomatic analyses suggested that there was diversity within the ITS region among these HCF products.

Conclusions: These PCR techniques allow the rapid diagnosis of HCF directly from equine clinical samples. The identification of HCF in blood raises questions about the pathogenesis of HCF in horses and warrants further investigation.

Acknowledgements: We thank the SPANA Ethiopia team; participating cart-horse owners; the Ethio-Belgian project; Addis Ababa University; Gabrielle Laing and the PHE UK Mycology reference laboratory.

Ethical animal research: Ethical approval for the project was awarded from the University of Liverpool and The College of Veterinary Medicine and Agriculture, Addis Ababa University. Sources of funding: SPANA UK (registered charity), the Institute of Infection and Global Health, University of Liverpool and an Sfam studentship. Competing interests: Dr Stringer was veterinary director at SPANA while this project was conducted and provided consultative and logistical input.

A NEGLECTED AND EMERGING HELMINTHOSIS: A CASE OF EQUINE FASCIOLOSIS

fGetachew, M.A., innocent, G., §Reid, S.W.J., fBurden, F. and 'Love, S. fDonkey Sanctuary, Sidmouth, Devon, EX10 0NU, UK; *Biomathematics and Statistics Scotland (BIOSS), The King's Buildings, Mayfield Road, Edinburgh, EH93JZ, UK; §Royal Veterinary College, University of London, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire, AL9 7TA, UK; #University of Glasgow, School of Veterinary Medicine, Large Animal Clinical Sciences and Public Health, Institute of Biodiversity Animal Health and Comparative Medicine, Glasgow, G61 1QH, UK. Email: getachew.mulugeta@thedonkeysanctuary.org.uk

Reasons for performing study: Although fasciolosis is an important livestock disease worldwide, the public health importance of human fasciolosis has increased in recent years and it is recognised as an important re-emerging zoonotic disease, its epidemiology and pathogenicity in donkeys, and the epidemiological role they may play have not been determined.

Objectives: To investigate the epidemiology and pathogenicity of fasciolosis in donkeys.

Study design: Cross-sectional coprological and retrospective post-mortem study.

Methods: Faecal samples collected from 803 randomly selected working donkeys from the central region of Ethiopia were analysed by a sedimentation-centrifugation-flotation technique. Further data on liver-flukes and associated pathologies were obtained by routine post mortem examinations of 112 donkeys, subjected to euthanasia on welfare grounds or died. Data were analysed using a generalised linear model and multivariate binary logistic regression in R statistical package with significance level of statistical tests set at P<0.05.

Results: Infection prevalences of 44.4% and 41.9% were obtained in coprologically and post mortem examined donkeys, respectively, irrespective of their age. Both Fasciola hepatica and Fasciola gigantica were identified with the mean infection intensity of 30 flukes. Older donkeys (>8 years) were found harbouring a significantly higher worm burden (P<0.0001). Gross and histopathologies of hyperplasia and thickening of the bile ducts, fibrosis of large portal areas and irregularbile duct proliferation and hypertrophy were noted.

Conclusions: The high infection prevalence of fasciolosis and the associated hepatic pathologies in working donkeys shows not only the susceptibility of donkeys and the impact it has on their health, but also indicates the important role they can play in the epidemiology of both livestock and human fasciolosis. These further demonstrate the need for these animals to be considered in the overall epidemiological studies and for sound control strategies and prevention of fasciolosis.

Ethical animal research: The research underwent ethical review and the use of animals was approved by the Directors of The Donkey Sanctuary. Consent of the owners was obtained to use their animals. Source of funding: The Donkey Sanctuary. Competing interests: None declared.

FACTORS AFFECTING COMPLICATION RATES WITH SUBPALPEBRAL LAVAGE CATHETER USE IN HORSES

tCornelissen, S., ^Finding, E., fBowen, I.M., §Bullard, C. and +Hallowell, G.D. fSchool of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Loughborough, Leicestershire, LE12 5RD, UK;*Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire, AL9 7TA, UK; §Defence Animal Centre, Melton Mowbray, Leicestershire, LE13 0GX, UK.

Email: svyslco@exmail.nottingham.ac.uk

Reasons for performing study: Subpalpebral lavage (SPL) systems are commonly used to facilitate treatment of ophthalmic conditions in the horse, are placed in differing positions and are associated with various complications.

Objectives: To evaluate differences in complication rates between SPL placement in the upper vs. lower eyelid and factors associated with development of complications.

Study design: Retrospective, clinical study.

Methods: Clinical records from the Royal Veterinary College (2000-2013) were evaluated. Data collated included age, breed, sex, clinician, training, ophthalmic condition, pharmacological agents administered, catheter position, duration of placement, where the catheter was managed (hospital/home) and any complications observed. Data was initially interrogated using chi-squared tests and then binary logistic regression models built to evaluate these factors.

Results: Data was obtained from 135 horses aged 6 days to 30 years. Duration of SPL was 3-60 days (median 8; IQR 7-15). Complication rates were lowest for medicine residents (10%), when compared with interns (42%), medicine clinicians (27%) and surgeons (16%). There was no difference in complication rate between SPL management at home (15.4%) compared with the hospital (16.1%; P = 0.94). Position of catheter placement was influenced by stage of training (P = 0.04; boarded clinicians were more likely to place in lower eyelid) and associated with duration of treatment (P = 0.03; longer treatment times with SPLs in upper eyelid). Complications were associated with catheter position (P = 0.03; upper 12.8%; lower 22.2%), antimicrobial administration (P = 0.008; 13.2% when used; 25.0% when not) and plasma administration (P = 0.004; 30.4% when used; 13.0% when not).

Conclusions: Subpalpebral lavage placement in the upper eyelid was associated with fewer complications. Use of antimicrobials appeared protective against complications and plasma should only be administered when indicated as it was associated with increased complications.

Ethical animal research: This project was reviewed by the University of Nottingham Ethics and Welfare Committee. Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: None. Competing interests: None declared.

DETECTION OF THE TOXIN HYPOGLYCIN A IN PASTURED HORSES AND IN THE EUROPEAN SYCAMORE MAPLE TREE (ACER PSEUDOPLATANUS) DURING TWO OUTBREAKS OF ATYPICAL MYOPATHY IN SWEDEN

fGrondahl G., *Berglund, A., §Skidell, J., fBondesson, U. and fSalomonsson, M.

National Veterinary Institute, Uppsala, Sweden; *Distriktsveterinarerna, Flyinge, Sweden; §Evidensia Specialist Horse Hospital, Helsingborg, Sweden.

Email: gittan.grondahl@sva.se

Reasons for performing study: Hypoglycin A (HG) appears to cause atypical myopathy (AM), but to our knowledge, detection of HG in affected and unaffected horses and concurrently in plants that they were exposed to has not previously been reported.

Objectives: To investigate HG in samples from horses exposed to Acer pseudoplatanus (European sycamore maple) and in such plant material, at the time of clinical cases of AM in the herd.

Study design: Cross-sectional study.

Methods: Blood was collected from 2 horses with AM and 22 clinically healthy co-grazing horses in 2 Swedish farms within one week of onset of signs (May 2014) and one month later, after horses were moved to other pastures. Ten healthy control horses from unaffected farms were sampled once. Samaras, seedlings, flowers and leaves from Acer pseudoplatanus and from Acer platanoides L (Norway maple) were collected from affected pastures. Hypoglycin A was analysed using chemical derivatisation with dansyl chloride (DNS) and ultra high performance liquid chromatography-tandem mass spectrometry. Hypoglycin A was detected as derivatised compound HG-DNS [M+H]+ with selected reaction monitoring.

Results: Hypoglycin A was detected in the horses affected with AM, and also in 20 out of 22 co-grazing horses. One month later, a surviving case horse and 9/20 co-grazing horses were still positive for HG. Controls from other farms were negative for HG. Hypoglycin A was detected in plant material from Acer pseudoplatanus, but not from Acer platanoides L.

Conclusions: Horses grazing in pastures with HG-containing Acer pseudoplatanus were positive for HG in blood, and some showed severe signs of myopathy.

Ethical animal research: Ethical consent for blood sampling was granted (C113/11) and horse owners gave their informed consent to inclusion of horses in the study. Source of funding: National Veterinary Institute, Sweden. Competing interests: None declared.

LONGITUDINAL OBSERVATIONS OF SILENT CARRIERS OF STREPTOCOCCUS EQUI IN A SWEDISH YARD

fGröndahl, G., fBäverud, V., fLjung, H., fMelys, V., fAspan, A. and ♦Riihimäki, M.

fNational Veterinary Institute, SE-750 07 Uppsala, Sweden; *Department of Clinical Sciences, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, Uppsala, Sweden. Email: gittan.grondahl@sva.se

Reasons for performing study: When managing strangles in horses, it is crucial to detect chronic infection with Streptococcus equi (SE), i.e. silent carriers.

Objectives: Evaluate diagnostics forSE carriers overtime in a farm.

Study design: Longitudinal observational study.

Methods: Sixty-three Icelandic horses isolated on an island were studied 4 to 26 months after remission of acute strangles, including repeated clinical examination and collection of blood, nasopharyngeal lavage (NPL), and guttural pouch lavage (GPL) samples. Twenty-two horses were treated with penicillin locally and systemically. Serology forS. equi was examined by iELISA [1]. Nasopharyngeal lavage and GPL samples were investigated forS. equi and S. zooepidemicus by real-time PCR [2].

Results: Thirty-three per cent were SE carriers after 15 months, despite repeated penicillin treatment. In 16/18 carriers, GPL samples were PCR-positive, but not NPL samples, whereas the opposite was true in 2 horses. Several carriers with persistent aerocystitis were not detected by3 consecutive NPL samples. Five of 18 carriers were seronegative (27.8%) at 15 months. Following conservative treatment, 7 of these 18 carriers were still carriers at 20 months, 8 were negative, and 3 were lost for sampling. Only GPL samples were positive at this point, and only 1/7 carriers were seropositive.

Conclusions: To detect chronic carriers of strangles, RT-PCR analysis from both GPL and NPL samples may be necessary. Serological screening at individual level often misses individual carriers in long-term cases.

Ethical animal research: The testing was approved by the Swedish Ethical Committee on Animal Experiments and horse owners gave their informed consent for inclusion of animals in the study. Source of funding: The Swedish-Norwegian Foundation for Equine Research. Competing interests: None declared.

References

1. Robinson, C., Steward, K.F., Potts, N., Barker, C., Hammond, T.A., Pierce, K., Gunnarsson, E., Svansson, V., Slater, J., Newton, J.R. and Waller, A.S. (2013) Combining two serological assays optimises sensitivity and specificity for the identification of Streptococcus equi subsp. equ exposure. Vet. J. 197,188-191.

2. Baverud, V., Johansson, S.K. and Aspan, A. (2007) Real-time PCR for detection and differentiation of Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus. Vet. Microbiol. 124, 219-229.

EXPRESSION OF INSULIN-RELATED GENES AND RELEASE OF NON-ESSENTIAL FATTY ACIDS (NEFA) FROM NECK CREST FAT COMPARED TO ABDOMINAL, MESENTERIC, AND TAIL PAD FAT IN HORSES

Bernhardsson, M.G. and Berg, L.C.

Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Hoejbakkegaard Allé 5, 2630 Taastrup, Denmark. Email: lcb@sund.ku.dk

Reasons for performing study: Regional adiposity on the neck crest has been linked to increased risk of developing equine metabolic syndrome (EMS). However, little is known about inherent metabolic differences between adipose tissues.

Objectives: To investigate innate differences between adipose tissue from neck crest compared to abdominal, mesenteric, and tail head in horses with no diagnosis of EMS.

Study design: Cross-sectional study.

Methods: Seven horses with no history of metabolic disorders were subjected to euthanasia for nonclinical reasons. They were selected randomly (5 geldings/2 mares; age 6-26 years; 110-165 cm height; BCS 3-8) and included with owners' consent. Adipose tissue was collected from neck crest, abdominal tissue, small intestine mesentery, and tail pad. mRNA expression of insulin-associated genes GLUT1, GLUT4, INSR and

RBP4, and inflammation-associated genes SAA, TNFa, IL-1P, IL-6, MCP-1 and PAI-1 were investigated using RT-qPCR. Morphology and adipocyte size were investigated by histology. Release of non-essential fatty acids (NEFA) was investigated before/after adrenaline stimulation in 4 horses.

Results: No significant differences were found in mRNA expression of metabolic and inflammation related genes between tissues. Adipose tissue from neck crest was more heterogeneous than abdominal fat (P = 0.001) and mesenteric fat (P = 0.01). Neck crest adipocytes were similar in size to abdominal adipocytes, and larger than adipocytes from tail head and mesentery. Basal levels of NEFA release were not different between tissues. Adrenaline stimulation caused a significant release of NEFA from visceral fat (abdominal P = 0.03; mesenteric P = 0.048).

Conclusions: This preliminary study introduces new metabolic genetic markers and NEFA to the field of metabolic research. No innate differences were shown for neck crest fat except in histology. Further studies in a case-control study design are needed to determine if neck crest fat is a risk factor for EMS.

Ethical animal research: Horses were subjected to euthanasia according to Danish Law and Danish ethical regulatory guidelines. Samples were used for research purposes with owners' consent. Source of funding: Hesteafgiftsfonden (Danish Horse Levy Board). Competing interests: None declared.

THYROID HORMONE AND THYROTROPIN CONCENTRATIONS AND RESPONSES TO THYROTROPIN RELEASING HORMONE IN AGEING HORSES

Breuhaus, B.A.

North Carolina State University, Raleigh, North Carolina, USA. Email: betta_breuhaus@ncsu.edu

Reasons for performing study: Thyroid hormones (THs) decrease with age in healthy dogs and cats, although they tend to remain within established reference ranges. Thyrotropin (TSH) is increased in elderly people, with or without mild alterations in THs.

Objectives: To test the hypothesis that geriatric horses will have lower THs and/or higher TSH compared with younger horses.

Study design: Cross-sectional study.

Methods: Resting THs and TSH, and responses to thyrotropin releasing hormone (TRH) were compared between young and old horses. Data from 71 normal, healthy horses that had participated in prior research projects were examined, and found to contain 42 horses 3-10 years of age, 16 horses >15 years and 10 horses >20 years. All samples had been assayed in the same previously validated radioimmunoassays. Statistical analysis was performed with commercial software.

Results: Although lower, THs were not significantly different between young and old horses when compared with the Mann-Whitney rank sum test. However, TSH concentration was significantly higher in horses aged >20 (median 0.52 ng/ml) or >15 years (0.44 ng/ml) compared to younger horses (0.33 ng/ml). TRH stimulation tests were performed in 19 of the younger horses, 7 of the horses >20, and 11 of the horses >15. Two-way repeated measures ANOVA on ranks revealed no significant differences in TH responses to TRH. The TSH response to TRH appeared to be slightly greater in the older horses, but did not quite reach significance (P = 0.06).

Conclusion: Similar to reports in elderly humans, aged horses have higher serum TSH concentrations than younger horses.

Ethical animal research: All horses in this study were part of a NCSU IACUC approved study. Owners gave informed consent for their horses' inclusion in the study. Sources of funding: College of Veterinary

Medicine North Carolina State University, USA Equestrian. Competing interests: None declared.

BASAL INSULIN AND INSULIN DYSREGULATION IN OBESE AND NON-OBESE ANDALUSIAN HORSES WITH AND WITHOUT CRESTY NECK

fMartin Giménez, T., *Aguirre Pascasio, C.N. and fde Blas Giral, I. department of Animal Pathology, Faculty of Veterinary Sciences, University of Zaragoza, Spain; *Veterinary Teaching Hospital, University of Murcia, Spain.

Email: tamara.martin.gimenez@gmail.com

Reasons for performing study: Andalusian horses have been proposed as a breed predisposed to equine metabolic syndrome (EMS) phenotype [1] because they are prone to exhibiting regional, generalised adiposity and tendency to laminitis [2]. Insulin dysregulation represents the main pathophysiological cause for all the features of EMS, however there are no epidemiological studies in this breed.

Objective: To assess insulin dysregulation through insulin proxies in Andalusian horses with different levels of obesity.

Study design: Cross-sectional study.

Methods: One hundred and sixty-four Andalusians (78 stallions and 86 mares, 2-15 years) were scored for overall (body condition score, BCS) and neck (cresty neck score, CNS) adiposity. Grain concentrate was withheld for 12 h before sampling. Blood samples were collected between 06.00-10.00 h for basal glucose, insulin concentrations, RISQI and MIRG proxies calculation. Conditions were defined as: obese horses (Ob), BCS > 7; cresty neck horses (CN), CNS > 3; hyperinsulinaemia, insulin >20 |xu/ml; low insulin sensitivity, RISQI<0.32[mu/l]-05 and increased insulin secretory response, MIRG>5.6muinsulin2/[10.l.mgglucose]. Regarding BCS 2 groups were created: Ob and non-Ob. These groups were subdivided depending on CNS: with CN and without it (nonCN). Ob-nonCN group (n = 2) was excluded for the statistics due to the low number of horses.

Results: Of the horses studied, 26.8% were Ob-CN, 42.1% were nonOb-CN and 31.1% were nonOb-nonCN. Ob horses presented higher insulin levels (P = 0.034) and lower RISQI values (P = 0.019) than all nonOb horses. When CN was considered, only RISQI was lower (P = 0.015) in Ob-CN group respect to nonOb-nonCN, however nonOb-CN group does not differ from the other 2 groups. Furthermore, the percentage of Ob-CN horses with hyperinsulinaemia (2.3%), abnormal RISQI (4.5%) and MIRG (9.1%) was very low.

Conclusions: These results suggest that in Andalusians, increased adiposity was not clearly associated to insulin dysregulation and, similar to human beings, may coexist as a metabolically healthy but obese phenotype.

Ethical animal research: Ethical University Committee approved all the procedures and owner informed consent was obtained. Source of funding: None. Competing interests: None declared.

References

1. Bamford, N.J., Potter, S.J., Harris, P.A. and Bailey, S.R. (2014) Breed differences in insulin sensitivity and insulinemic responses to oral glucose in horses and ponies of moderate body condition score. Dom. Anim. Endocrinol. 47,101-107.

2. Riber, C., Rubio, M.D., Marquez, F., Pinedo, M., Munoz, A. and Castejon, F. (1995) Haematological changes observed in Andalusian horses with laminitis. J. Vet. Med. Sci. 57, 981-984.

TRIAMCINOLONE ADMINISTRATION DOES NOT INCREASE OVERALL RISK OF DEVELOPING LAMINITIS

Hammersley, E., Duz, M. and Marshall, J.F.

Weipers Centre Equine Hospital, School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, 464 Bearsden Road, Glasgow, G61 1QH, UK. Email: 1105240H@student.gla.ac.uk

Reasons for performing study: Triamcinolone is commonly used in equine practice for the treatment of orthopaedic conditions. A serious potential adverse effect of triamcinolone is laminitis. However, evidence forthe risk of laminitis associated with triamcinolone use is limited.

Objectives: To determine the risk of laminitis within 90 days of triamcinolone administration and compare with the risk of laminitis in a veterinary-attended horse population.

Study design: Retrospective study of clinical records.

Methods: Text mining and data extraction was performed using content analysis software (SimStat-WordStat v.6) on a database of anonymous digital clinical records from a convenience sample of North American equine practices (n = 9). Medical records were retrieved using a dictionary of keywords for 3 groups of horses: 1) treated with triamcinolone, 2) age and practice matched control population (no triamcinolone) and 3) all laminitic horses. Records of horses within Groups 1 and 2 were mined for evidence of laminitis within a 90-day period of treatment or a random date respectively. Data manipulation and analysis was performed using Rv3.0.0 (R Development Core Team). The prevalence of laminitis within all groups was determined and relative risk of developing laminitis determined by single logistic regression.

Results: The clinical records of 225,777 horses were examined. Overall prevalence of laminitis within the database was 1.1% (n = 2533). Triamcinolone was administered to 12.4% (n = 27,898) horses and 0.07% of treated horses (n = 20) developed laminitis. In the control population (n = 56,695), 0.2% of horses (n = 134) developed laminitis. The risk of developing laminitis was significantly lower in the triamcinolone treatment group than the control population (OR 0.3 95%CI, 0.18-0.48 P<0.001).

Conclusions: Triamcinolone treatment does not increase the overall risk of a horse developing laminitis. However, further investigation of risk factors for laminitis in the 20 horses identified by this preliminary study is warranted to aid development of evidence-based treatment guidelines.

Ethical animal research: This study was approved by the Ethics and Welfare Committee of the School of Veterinary Medicine at the University of Glasgow. Owners gave informed consent for their horses' inclusion in the study. Sources of funding: John Crawford Endowment Fund, University of Glasgow. Competing interests: None declared.

INFORMED HYPOTHETICO-DEDUCTIVE REASONING BASED ON CLINICAL SIGNS FOR DIAGNOSIS OF EQUINE LAMINITIS USING DECISION TREE ANALYSIS

t*Wylie, C.E., §Shaw, D.J.,'Verheyen, K.L.P. and fNewton, J.R. Epidemiology Department, Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, CB8 7UU, UK; *Rossdales Equine Hospital, Cotton End Road, Exning, Newmarket, Suffolk, CB8 7NN, UK; §Royal (Dick) School of Veterinary Studies and The Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian, EH25 9RG, UK; #Veterinary Epidemiology and Public Health Group, Department of Veterinary Clinical Sciences, Royal Veterinary College, North Mymms, Hatfield, Hertfordshire, AL9 7TA, UK. Email: claire.wylie@rossdales.com

Reasons for performing study: Effective diagnosis of equine laminitis is necessary to allow prompt instigation of palliative and therapeutic treatments, yet there has been limited work regarding diagnostic accuracy.

Objectives: To compare the prevalence of clinical signs in laminitis and non-laminitis lamenesses to evaluate the capabilities of discrimination for differential diagnosis.

Study design: Analytical epidemiological study.

Methods: Veterinary practitioners completed a pre-designed checklist of laminitis-associated clinical signs identified by literature review, for equine lameness of any origin. A case was defined as a horse/pony with veterinary-diagnosed, clinically apparent laminitis, attended by a participating practitioner. Associations between clinical signs and case/control status were tested by logistic regression with adjusted odds ratios and 95% confidence intervals, with veterinary practice as a fixed effect, and Wald P-value calculated. Multivariable analysis using graphical classification tree-based statistical models allowed comprehension of the prevalence in the data associated with particular clusters of clinical signs.

Results: Data were collected for588 laminitis cases and 201 non-laminitis lamenesses. The overall prevalence of specific clinical signs ranged from 2.7% for'sole prolapse' to 85.0% for'lame at trot'. Differences in prevalence ranged from-14.1% for'lame at trot' (more common in controls) to +71.9% for 'short stilted gait at walk' (more common in cases). Five clinical signs had a difference in prevalence of greater than +50%: 'reluctance to walk', 'short, stilted gait at walk', 'difficulty turning', 'shifting weight' and 'increased digital pulse'. Bilateral forelimb lameness was the best discriminator (92% of animals with this clinical sign had laminitis). The additional presence of increased digital pulses improved this to 99%. Flat/convex sole, shifting weight and short stilted gait at walk were also useful discriminators.

Conclusions: This is the first study to provide information aiding diagnostic hypothetico-deductive reasoning based on clinical signs to differentially diagnose laminitis from other lamenesses.

Ethical animal research: Ethical approval obtained from Royal Veterinary College. Owners gave informed consent for their horses' inclusion in the study. Sources of funding: Project funded by World Horse Welfare. C.E. Wylie currently funded by The Margaret Giffen Charitable Trust. Competing interests: None declared.

AN ANATOMICAL STUDY OF THE DORSAL AND VENTRAL NASAL CONCHAL BULLAE IN NORMAL HORSES: GROSS MORPHOLOGY AND HISTOLOGICAL FEATURES

Froydenlund, T.J., Dixon, P.M., Smith, S.H. and Reardon, R.J.M. Royal (Dick) School of Veterinary Studies, Easter Bush Campus, Roslin, Midlothian, EH25 9RG, UK. Email: tim.froydenlund@ed.ac.uk

Reasons for performing study: The morphology of the dorsal (DCB) and ventral (VCB) nasal conchal bullae, including their cellulae, drainage and histology, are poorly described. The recent recognition that these bullae can become infected, causing chronic unilateral nasal discharge has stimulated interest in these structures. A more complete understanding of their anatomy would be useful in the diagnosis and treatment of their disorders.

Objectives: To document the structure, drainage and histology of the equine DCB and VCB.

Study design: Descriptive.

Methods: Fourteen fresh cadaveric horse heads, were transected sagittally midline and dissected to expose the nasal conchal bullae. The dimensions of each bulla, the number of drainage apertures, the number of cellulae and orientation of the septae were recorded. Representative samples were collected for histopathology.

Results: The mean lengths of the DCB and VCB were 77.7 mm (range 48-105 mm) and 57.1 mm (range 34-86 mm) respectively; equivalent to 13.8% and 10.2% of skull length, respectively. The mean widths of the DCB and VCB were 28.5 mm (range 21-35 mm) and 28.2 mm (range 13-41 mm) respectively; equivalent to 5.1% and 5% of skull length respectively. The median numberofdrainage apertures from the DCB and VCB were 2 and 1 respectively. The median number of cellulae within the DCB and VCB were 3 and 2, respectively. No communications were identified between the DCB and VCB and the adjacent paranasal sinuses. Histology revealed that the bullae consisted of ciliated, pseudostratified, columnar epithelium supported by a glandular submucosa often overlying turbinate bone and, variably, hyaline cartilage.

Conclusions: The morphology of the equine nasal conchal bullae is quite variable. The DCB is generally a more complex structure than the VCB, containing more septae, cellulae and drainage apertures. This more detailed description of DCB and VCB anatomy will hopefully facilitate successful treatment of their disorders.

Ethical animal research: Research ethics committee oversight not currently required by this conference: the study was performed on material obtained from an abattoir. Source of funding: None. Competing interests: None declared.

PREVALENCE OF AND RISK FACTORS FOR RECURRENT AIRWAY OBSTRUCTION IN GERIATRIC HORSES AND PONIES

Ireland, J.L., *Christley, R.M., *McGowan, C.M., *Clegg, P.D. and ♦Pinchbeck, G.L.

fAnimal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, CB8 7UU; *School of Veterinary Science, University of Liverpool, Leahurst Campus, Neston, Wirral, CH64 7TE, UK. Email: jo.ireland@aht.org.uk

Reasons for performing study: Respiratory disease is a common cause of morbidity in geriatric horses, with a high prevalence of respiratory clinical signs; increasing with increasing horse age. However, owners frequently do not attribute these signs to disease and may not seek veterinary attention.

Objectives: To estimate the prevalence of recurrent airway obstruction (RAO) in the British geriatric equine population using a risk-screening questionnaire (RSQ) and identify factors associated with RAO.

Study design: Cross-sectional.

Methods: Owners of geriatric horses/ponies enrolled in a previous cohort study were sent a postal questionnaire, combining a validated RSQ with questions regarding management, preventive healthcare, and respiratory-specific clinical signs. An RSQ score of >0.87 was the positive cut-off for RAO. Factors associated with RAO were assessed using multivariable logistic regression.

Results: The useable response rate was 43.1%, providing data for 285 horses/ponies (median age 23.3 years). Coughing within the preceding year (27.0%) was the most prevalent owner-reported clinical sign. Among the study population, the apparent prevalence of RAO using the RSQ was 20.7%. 10.5% of horses/ponies were reported to have veterinary-diagnosed RAO (median age at diagnosis 13 years), of which 33.3% had a positive RSQ score. Data from 273 animals were included in the multivariable model, and factors associated with increased risk of RAO were ridden exercise >4 days/week (odds ratio [OR] 3.64; P = 0.005) compared to no exercise; residing on a farm (OR 4.99; P = 0.04) compared to residing on the owner's home premises and having had a respiratory infection within the past 12 months (OR4.87; P<0.001).

Conclusions: Risk-screening questionnaire score-determined RAO prevalence was considerably higher than the proportion of animals previously diagnosed with RAO. This suggests under-diagnosis of respiratory problems in geriatric horses, much of which may be unrecognised orundiagnosed RAO. Riskfactors identified differfrom those previously reported forthe general equine population.

Ethical animal research: This study was granted institutional ethical approval from the University of Liverpool and the Animal Health Trust. Return of a completed postal questionnaire was taken as informed owner consent. Sources of funding: The original cohort study was funded by the Horse Trust and this study was funded by the Animal Health Trust. Competing interests: None declared.

DO BALF CYTOKINE PROFILES VARY DEPENDING ON THE SAMPLED LUNG IN HORSES WITH UNILATERAL IAD-CONSISTENT CYTOLOGY?

t*Hue, E., tOrard, M., §Depecker, M., §Couroucé-Malblanc, A., 'Paillot, R., t*Pronost, S. and tRichard, E.A.

tLABÉO Frank Duncombe; 1 Route de Rosel, 14053 Caen Cedex 4, France; *Normandie Univ, UNICAEN, SF4206 ICORE, EA 4655 U2RM, 14032 Caen, France; §LUNAM Université, ONIRIS, UPSP 5304, Atlanpôle - La Chantrerie, BP40706, Nantes, F-44307, France; #Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, CB8 7UU, UK. Email: eric.richard@calvados.fr

Reasons for performing study: Little data on BALF cytokine profiles are available from racehorses with IAD; cytological diagnosis being most frequently made from one lung only per horse.

Objectives: To compare cytokine mRNA expressions and protein concentrations in BALF from both lungs of horses with unilateral IAD-consistent cytology.

Study design: Cross-sectional study.

Methods: As part of a larger study, 250 ml saline was randomly instilled in one lung and 500 ml in the contralateral lung of 30 clinically healthy Standardbred racehorses. This procedure was repeated 72 h later, inversing the volume per lung. Cytological cut-off values for IAD diagnosis was neutrophil proportions >10% when instilling 250 ml. For these samples, mRNA expression and concentrations of IL-1 p, IL-4, IL-8, IL-10, IL-17, TNF-a and IFN-y were determined byRT-qPCRand ELISA.

Results: Eleven horses had BALF with IAD- and CTL-consistent cytology from, respectively, each lung, and were enrolled in the study (22 samples). Data were not significantly influenced by the sampling day, and BALF total cell counts or cytokine concentrations were not significantly different among lungs. Relative mRNA expression of IL-1 p (3.887 ± 3.082; P = 0.01) and IL-10 (3.225 ± 1.710; P = 0.005) were significantly higher in BALF of IAD- compared to CTL consistent lungs (respectively 1.408 ± 1.118 and 1.488 ± 1.393); and also correlated to neutrophil proportions (respectively r = 0.54; P = 0.01 and r = 0.65; P = 0.001).

Conclusions: Differences in cytokine mRNA expression were associated with IAD- or CTL consistent BALF cytology in the same racehorses in training. These findings suggest that specific local immune reactions or regulation within the lower airways should be considered in IAD.

Ethical animal research: The study was approved by the Regional Animal Ethic Committee, and informed consent was provided by all horse owners. Sources of funding: LABÉO, CISCO-Oniris and AVEF (French Association of Equine Practitioners). Competing interests: None declared.

COMPARISON OF NANOPARTICULATE CpG IMMUNOTHERAPY WITH AND WITHOUT ALLERGENS IN RAO-AFFECTED HORSES

tKlier, J., tttGeis, S., fttSteuer, J., 'Reese, S., §Fuchs, S., »Mueller, R.S., §Winter, G. and fttGehlen, H.

fCentre for Clinical Veterinary Medicine, Equine Clinic, *Small Animal Medicine Clinic, §Department of Pharmacy, Pharmaceutical Technology and Biopharmacy, 'Department of Veterinary Science, Instituteof Anatomy, Histology and Embryology, Ludwig Maximilians University, Munich, Germany; ffFree University of Berlin, Department of Veterinary Medicine, Equine Clinic, Surgery and Radiology, Berlin, Germany. Email: j.klier@pferd.vetmed.uni-muenchen.de

Reasons for performing study: New therapeutic strategies to modulate immune responses in human and equine allergic airway diseases are under extensive investigation. Stimulation of Treg cells with immune modulating agents is a novel therapeutic option.

Objectives: The aim of this field study was to compare the effects of a nebulised nanoparticulate CpG immunotherapy (CpG-GNP) with and without specific allergens.

Study design: Longitudinal clinical study comparing 2 therapeutic options.

Methods: Twenty RAO-affected horses were divided into 2 treatment groups (CpG alone and CpG with allergens). Two specific allergens were selected for each horse according to anamnesis and a functional in vitro test. Treatments were given by nebulisation 7 times and the horses were examined 3 times: baseline (I), after the treatment course (II), and after 6 weeks later (III). Clinical parameters, indirect intrapleural measurement, arterial blood gas, amount of tracheal mucus and neutrophil percentage were evaluated.

Results: CpG alone resulted in a significant improvement in clinical parameters and a significant reduction of tracheal mucus after treatment and at 6 weeks post treatment. After CpG plus specific allergens, there was significant improvement of 70% of examined parameters. However, there were no significant differences in the results compared with CpG-GNP treatment alone.

Conclusions: There were no significant differences between treatment groups. CpG-GNP immunotherapy alone produced a potent and persistent effect on allergic and inflammatory parameters and may have potential as fortreatment of equine and human allergic inflammatory airway diseases.

Ethical animal research: The study was approved by the regional legal agency for animal experiments of the Government of Bavaria, Germany (No. 55.2-1-54-2531-31-10). Owners gave informed consent for their horses' inclusion in the study. Sources of funding: Partly supported by the Deutsche Forschungsgemeinschaft (DFG) (Germany) (GE'2044/4-1). The AeroNeb Go™ vibrating mesh nebuliser (Aerogen, Galway, Ireland) was sponsored by Inspiration Medical (Bochum, Germany). Competing interests: None declared.

ULTRASONOGRAPHIC IDENTIFICATION OF THE PULMONARY VEINS IN ADULT HORSES

Van Loon, G., »Vandecasteele, T., »Vandevelde, K., tDecloedt, A., tDe Clercq, D. and »Cornillie, P.

fDepartment of Large Animal Internal Medicine and department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.

Email: gunther.vanloon@ugent.be

Reasons for performing study: In man, pulmonary veins (PV) are of major importance in atrial fibrillation pathophysiology as ectopy often

© 2015 The Author(s). Equine Veterinary Journal 47,Suppl. 48 (2015) 2-28

Equine Veterinary Journal © 2015 EVJ Ltd

originates in atrial myocardial sleeves extending in the PV wall. In addition, PV size on ultrasound is used to assess left atrial volume overload. In horses, PV anatomy and ultrasound have hardly been studied.

Objectives: To study PV anatomy and establish a standard approach for echocardiographic identification of the PVfrom a right and left parasternal view.

Study design: Anatomical and echocardiographic description.

Methods: Firstly, post mortem left atrial and PV silicone corrosion casts were made in 10 horses to investigate normal PV anatomy. Secondly, left and right parasternal ultrasound images and silicone casts were made in 3 horses, to compare images and casts.

Results: Four major PVostia were identified on the casts, draining specific lung areas. From a right parasternal longitudinal view, ostium III was identified between the right atrial wall and right pulmonary artery, and ostium II left-dorsal to it. From a left parasternal oblique short-axis view, ostium III, its antrum and side-branches were used as anatomical landmarks (adjacent to the right atrial wall). Slightly more caudal, ostium II was visualised with, in one horse, its antrum and 2 branches. Ostium I was only seen in one horse, slightly ventral to ostium II. Ostium IV was always identified in cross-section on a left short-axis view, left to the pulmonary artery bifurcation.

Conclusions: A standard echocardiographic approach allows identification of pulmonary veins in adult horses. Left oblique and short axis views were superior although right long-axis views also showed ostiums II and III. These data allow reference values to be established for pulmonary venous size and flow, and to investigate new treatment strategies for atrial fibrillation.

Ethical animal research: Post mortem study with owner's informed consent; ultrasound with owner's informed consent. Study performed following the local ethical guidelines. Source of funding: Ghent University (institutional). Competing interests: None declared.

CAUSES OF PLEURAL EFFUSION IN HORSES IN THE UK

Johns, I. and McParland, T. Presented byT. Mair

Royal Veterinary College, Equine Referral Hospital, Hawkshead Lane,

North Mymms, Hatfield, Hertfordshire, AL9 7TA, UK.

Email: ijohns@rvc.ac.uk

Reasons for performing study: Pleural effusion (PE) is reported to occur most commonly secondary to bacterial pneumonia or lung abscesses, with neoplastic effusions contributing the minority of cases. The majority of these reports originate from America and Australia, where long distance transport of horses, a recognised risk factor, appears to occur more frequently. Anecdotally, neoplastic PE is more commonly diagnosed in the UK.

Objectives: To describe the causes of PE in horses resident in the UK, and to identify potential markers that can help differentiate between infectious and neoplastic causes of PE.

Study design: Retrospective clinical study.

Methods: Medical records from 4 referral hospitals in southern England were searched for horses diagnosed with PE. Information gathered from medical records included signalment, diagnosis (infectious vs. neoplastic), admission physical examination and biochemical findings, and characteristics of the effusion (volume, cell count, total protein [TP] concentration). Statistical comparisons were made between the neoplastic and infectious group using appropriate testing.

Results: Seventy horses were identified, of which 28 (40%) were neoplastic and 42 were infectious. Horses with infectious effusions were

significantly younger (median 7 vs. 13 years; P = 0.002) and had significantly smaller volumes of pleural fluid drained at admission (9.8 vs. 32.3 l; P<0.001). Horses with infectious PE had a significantly higher rectal temperature (38.6 vs. 38.2°C; P = 0.03), fibrinogen concentration (7.8 vs. 5.7 g/l; P = 0.02) and serum amyloid A concentration (223 vs. 104 mg/l; P = 0.02). Pleural fluid characteristics identified a significantly greater cell count and TP concentration in horses with infectious PE (47 x 109/l vs. 3.4x109/l; P<0.001; 54 vs. 31 g/l; P = 0.001).

Conclusions: These results suggest that in the UK neoplastic effusions account for a greater proportion of PE than previously reported. A large volume of PE in an older horse with a low cell count and TP concentration should increase the index ofsuspicion of neoplasia.

Ethical animal research: This was a retrospective study of clinical cases. Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: None. Competing interests: None declared.

POST EXERCISE CARDIAC TROPONIN I RELEASE AND CLEARANCE IN NORMAL STANDARDBRED RACEHORSES

tRossi, T.M., tPearl, D.L., *Pyle, W.G., 'Maxie, M.G., §Kavsak, P.A. and tPhysick-Sheard, P.W.

department of Population Medicine, Ontario Veterinary College, University of Guelph, Ontario, Canada; *Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Ontario, Canada; § Animal Health Laboratory, Laboratory Services Division, University of Guelph, Ontario, Canada; 'McMaster University, Department of Pathology and Molecular Medicine, Hamilton, Ontario, Canada. Email: rossit@uoguelph.ca

Reasons for performing study: There are currently no studies detailing cardiac troponin I (cTnI) release and clearance in normal horses post exercise using an analytically validated assay. These data are essential for selecting appropriate sampling times in equine athletes with suspected myocardial damage.

Objective: To plot the magnitude and time course of cTnI release and clearance, using a validated cTnI assay, after maximal effort.

Study design: Descriptive longitudinal study.

Methods: Five clinically normal Standardbred racehorses in full race training were included in the study. Physical examinations were performed on subjects and blood samples were taken via jugular venipuncture pre-exercise. Horses were exercised in harness at race intensity in groups on a training track. A second blood sample was taken immediately post exercise and an intravenous catheter was then placed in a jugular vein. Hourly blood samples were taken for 24 h. All samples were collected in red top serum Vacutainer® tubes and allowed to clot for 30 min before being centrifuged and serum harvested. Serum samples were stored at -80°C until analysis. All samples were analysed using the Abbott ARCHITECT STAT High Sensitivity cTnI® assay.

Results: Mean resting cTnI level was 1.33 ± 0.6 ng/l (range, 0.822.33 ng/l). All horses exhibited an increase in cTnI level after exercise with peak elevation occurring 2-6 h post exercise (mean, 4.6 ± 1.7 h). Mean peak increase in cTnI level was 11.96 ± 9.41 ng/l (range, 1.72-23.76 ng/l). All horses returned to baseline levels within 24 h.

Conclusions: All horses experienced an increase in cTnI post exercise, with the peak occurring 2-6 h post exercise. Further studies are needed to determine the significance ofthese increases.

Ethical animal research: The study protocol was approved by the University's Animal Care Committee. Explicit informed consent was

obtained in writing for all client-owned animals. Source of funding: Equine Guelph. Competing interests: Dr Kavsak has received grants/ honoraria/consultant/advisor fees from Abbott Laboratories, Abbott Point of Care, Beckman Coulter, Ortho Clinical Diagnostics, Randox Laboratories, Roche Diagnostics, and the Canadian Agency for Drugs and Technologies in Health. He is listed as an inventor on patents filed by McMaster University related to laboratory testing in acute cardiac care. No funding was received from the manufacturer of the assay evaluated in this study.

RETROSPECTIVE OBSERVATIONAL STUDY ON THE OUTCOME OF MEDICAL TREATMENT OF ATRIAL FIBRILLATION

tLotstra, R.J., »van den Broek, J., §Power, T., 'Marr, C.M. and tWijnberg, I.D. fDepartment of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, the Netherlands; ^Department of Farm Animal Health, Dept. Epidemiology. Faculty of Veterinary Medicine, Utrecht University, the Netherlands; §Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire, AL7 9TA, UK; #Rossdales Equine Hospital and Diagnostic Centre, Cotton End Road, Exning, Newmarket, CB8 7NN, UK. Email: i.d.wijnberg@uu.nl

Reasons for performing study: Atrial fibrillation is a common equine arrhythmia. Quinidine alone, or with digoxin are common treatments. Studies on outcome in Warmblood populations in which duration of the AF is often unknown are limited.

Objectives: To identify the factors that are associated with the success of full treatment cardioversion with oral medication, and establish whether there are differences in these factors between institutions.

Study design: Retrospective case series using patient records of Equine University Clinic of Utrecht University and Rossdales Equine Hospital, Newmarket.

Methods: Forty-nine horses treated with quinidine were identified (29 Warmbloods, 20 Thorougbreds, 1 Anglo-Arabian). Details of signalment, history, duration physical examination and echocardio-graphy including left atrial size and presence of mitral regurgitation were retrieved. Clinical details including mean weight, age and left atrial size were compared between clinics using independent samples t test. Association between variables and cardioconversion were evaluated in a backwards logistic regression using Akaike's information criterium (AIC) and odds ratios were calculated. Factors were sex, clinic, breed, mitral regurgitation, duration and poor performance. Covariates were age, weight and the size of the left atrium. Significance was set at 0.05.

Results: Fifty-one horses (mean age 8.8 s.d. 4.5 years) were treated with quinidine sulfate, 18 also received digoxin. Eighty per cent converted to sinus rhythm. In 8 horses the known duration was less than 3 months. The only factor associated with successful treatment was the use of digoxin in combination with quinidine sulfate (odds ratio 12.4; 95% CI 2.61 and 91.85 according to AIC analysis).

Conclusions: In this retrospective case series, there is much potential for bias in the data; however, the use of digoxin in addition to quinidine was associated with improved conversion rates regardless of breed even though AF duration was unknown in most horses.

Ethical animal research: Research ethics committee oversight not currently required by this conference: retrospective study of clinical records. Explicit owner informed consent for inclusion of animals in this study was not stated. Source of funding: None. Competing interests: None declared.