Equine Clinical Medicine, Surgery and Reproduction

1056 Pages·2011·77.813 MB·English

by  Graham Munroe, Scott Weese

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Equine
Clinical Medicine
,
Surgery
, and
Reproduction
Graham A Munroe
BVSc (Hons), PhD, DipECVS, CertEO, DESM, FRCVS
Cowrig Cottage
Greenlaw, Duns
Berwickshire
Scotland, UK
J Scott Weese
DVM, DVSc, DipACVIM
Associate Profesor
Department of Pathobiology
Ontario Veterinary College
University of Guelph
Guelph
Ontario, Canada
MANSON PUBLISHING/THE VETERINARYPRESS
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Copyright © 2011 Manson Publishing Ltd
ISBN: 978-1-84076-119-1
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Contents
Contributors 5
Preface 7
Abbreviations 8
1 Musculoskeletal system _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 11
1.1 Approach to the lame horse 12
Cedric Chan and Graham Munroe
1.2 The foal and developing animal 40
Cedric Chan and Graham Munroe
1.3 The foot 62
Andrew Parks
1.4 The forelimb 102
Peter Milner
1.5 The hindlimb 136
Ehud Eliashar
1.6 The head 166
Martin Weaver
1.7 The axial skeleton 174
Martin Weaver
1.8 Soft-tissue injuries 186
Eddy Cauvin
2 Reproductive system _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 241
2.1 Female reproductive tract 242
Graham Munroe, Madeleine Campbell,
Zoë Munroe, and Matthew Hanks
2.2 Male reproductive tract 326
Theresa Burns, Tracey Chenier,
and Graham Munroe
2.3 Equine castration 374
Luis Lamas and Graham Munroe
3 Respiratory system _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 381
3.1 Introduction 382
Josh Slater
3.2 Surgical conditions of the upper respiratory tract 392
Bruce Bladon and Graham Munroe
3.3 Medical conditions of the upper respiratory tract 450
Josh Slater
3.4 Medical conditions of the lower respiratory tract 458
Joanne Hewson, Luis Arroyo, and Josh Slater
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4 Gastrointestinal system _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 481
4.1 Upper gastrointestinal tract 482
Henry Tremaine
4.2 Lower gastrointestinal tract 516
Scott Weese, Ludovic Boure, Simon Pearce,
and Nathalie Cote
5 Liver _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 598
Thomas Koch, Anthony Knight, and Scott Weese
6 Endocrine system _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 620
Babetta Breuhaus
7 Urinary system _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 637
Modest Vengust
8 Cardiovascular system _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 671
Kim McGurrin
9 Hemolymphatic system _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 709
Darren Wood and Sonya Keller
10 Nervous system _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 745
Siobhan McAuliffe and Nathan Slovis
11 Eyes _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 809
Heather Gray
12 Skin _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 873
Reginald Pascoe
13 Wound management
and infections of synovial structures _ _ _ _ _ _ _ _
939
Antonio Cruz and Graham Munroe
14 The foal _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 966
Sarah Stoneham and Graham Munroe
15 Behavioral problems _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 995
Katherine Houpt
Further reading 1012
Index 1020
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Contributors
Luis G Arroyo DVM, DVSc Nathalie Cote DVM, DVSc, DipACVS
Department of Clinical Studies Milton Equine Hospital
Ontario Veterinary College Milton, Ontario, Canada
University of Guelph
Guelph, Ontario, Canada Antonio CruzDVM, MVM, MSc, DrMedVet, DipACVS,
DipECVS
Bruce BladonBVM&S, CertEP, DESTS, DipECVS, MRCVS Hospital Director,
Donnington Grove Veterinary Surgery Paton and Martin Veterinary Services,
Newbury, Berkshire, UK Aldergrove, British Columbia, Canada
Ludovic BoureDVM, MSc, DipACVS, Dip ECVS Ehud EliasharDVM, DipECVS, MRCVS
Head of Experimental Surgery Lecturer in Equine Surgery,
AO Research Institute Department of Clinical Veterinary Sciences
Davos, Switzerland Royal Veterinary College
North Mymms, Hatfield, Hertfordshire, UK
Babetta Breuhaus DVM, PhD, DACVIM
Department of Clinical Sciences Heather E GrayDVM, DipACVO
North Carolina State University Oak Ridges Veterinary Professional Corporation
Raleigh, North Carolina, USA Claremont, Ontario, Canada
Theresa BurnsDVM, MSc, DipACT Matthew L HanksBVSc, MRCVS
Yarrow Station Lecturer in Reproduction
Chilliwack, British Columbia, Canada Division of Veterinary Clinical Studies
Royal (Dick) School of Veterinary Studies
Madeleine L H CampbellBVetMed(Hons), MA(Oxon), Easter Bush, Midlothian, Scotland, UK
PhD, DipECAR, MRCVS
Hobgoblins Stud and Equine Reproduction Centre Joanne HewsonDVM, PhD, DipACVIM
Duddleswell, Ashdown Forest, East Sussex, UK Department of Clinical Studies
Ontario Veterinary College
Eddy R J CauvinDrVétérinaire, MVM, PhD, HDR, CertVR, University of Guelph
CertES(Ortho), DipECVS Guelph, Ontario, Canada
Azurvet
Hippodrome de la Côte d’Azur, Katherine A HouptVMD, PhD, DACVB
Cagnes sur Mer, France James Law Professor of Animal Behavior
Department of Clinical Sciences
Cedric C-H ChanBVSc, DipECVS, CertES(Orth), MRCVS College of Veterinary Medicine
Northwest Equine Referrals Cornell University
Putney, London, UK Ithaca, New York, USA
Tracey ChenierDVM, DVSc DipACT Sonya KellerDVM, DVSc, DipACVP
Assistant Professor, Large Animal Theriogenology Clinical Pathologist
Ontario Veterinary College IDEXX Reference Laboratories
University of Guelph Markham, Ontario, Canada
Guelph, Ontario, Canada
Anthony P KnightBVSc, MS, MRCVS, DACVIM
Professor, Department of Clinical Sciences
College of Veterinary Medicine & Biomedical Sciences
Colorado State University
Fort Collins, Colorado, USA
5
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Thomas G KochDVM, PhD Candidate Josh D SlaterBVM&S, PhD, DipECEVIM, MRCVS
Department of Clinical Studies Professor of Equine Clinical Studies
Ontario Veterinary College Royal Veterinary College
University of Guelph North Mimms, Hatfield, Hertfordshire, UK
Guelph, Ontario, Canada
Nathan Slovis DVM, DipACVIM, CHT (Certified Hyper-
Luis RGP LamasDVM, CertES(Orth), MRCVS baric Technologist)
Rua de Junqueira 148, Hagyard Equine Medical Insititute
1300–1345 Lisbon, Portugal Director McGee Critical Care and Medical Center
Lexington, Kentucky, USA
Siobhan McAuliffeMVB, MRCVS, DipACVIM
Dreamland Farm Rehabilitation Center Sarah J StonehamBVSc, CertESM, MRCVS
Lexington, Kentucky, USA Lone Oak Stud
Hilborough, Norfolk, UK
M Kim J McGurrinDVM, DVSc, DipACVIM
Department of Clinical Studies W Henry TremaineBVet Med, MPhil, Cert ES, DipECVS,
Ontario Veterinary College MRCVS
University of Guelph Department of Clinical Veterinary Science
Guelph, Ontario, Canada School of Veterinary Science
University of Bristol, Langford, Bristol, UK
Peter I MilnerBVetMed, BSc, PhD, CertES(Orth), MRCVS
Lecturer, Equine Division Modest VengustDVM, DVSc, DipACVIM
Department of Veterinary Clinical Science Assistant Professor
Faculty of Veterinary Science Veterinary Faculty
University of Liverpool University of Ljubljana,
Neston, Wirral, UK Ljubljana, Slovenia
Graham Munroe BVSc (Hons), PhD, DipECVS, CertEO, Martin P Weaver BVMS, DrMedVet, PhD, DVR, MRCVS
DESM, FRCVS Senior Lecturer
Flanders Veterinary Services Division of Veterinary Clinical Studies
Greenlaw, Duns. Berwickshire, Scotland, UK Royal (Dick) School of Veterinary Studies
University of Edinburgh
Zoë J MunroeBVSc, MRCVS Easter Bush, Roslin, Midlothian, Scotland, UK
Flanders Veterinary Services
Greenlaw, Duns, Berwickshire, Scotland, UK J Scott WeeseDVM, DVSc, DipACVIM
Associate Professor, Department of Pathobiology
Andrew H ParksMA, Vet MB, MRCVS, CertVR, DipACVS Ontario Veterinary College
Professor, Large Animal Surgery University of Guelph
Department of Large Animal Medicine Guelph, Ontario, Canada
College of Veterinary Medicine
University of Georgia Darren WoodDVM, DVSc, DipACVP
Athens, Georgia, USA Associate Professor, Department of Pathobiology
Ontario Veterinary College
Reginald R PascoeAM, BVSc, DVSc, FRCVS, FACVSc University of Guelph
Adjunct Professor, Veterinary School Queensland Guelph, Ontario, Canada
Consultant, Oakey Veterinary Hospital
Oakey, Queensland, Australia
Simon PearceBVSc, PhD, DipACVS
Bio Innovation SA
Adelaide, South Australia, Australia
6
Preface
THE FIELDS of equine medicine, surgery, and repro- The scope of equine veterinary medicine makes it
duction have developed massively over the last 25–30 impossible for any one book to act as the sole resource for
years and new knowledge and techniques for the diag- all areas. With this in mind and considering the target read-
nosis and treatment of all sorts of conditions and diseases ership of this book, complicated or advanced diagnostic
continues to be added. This new knowledge is presented and treatment techniques are mentioned, but not covered
initially in scientific papers and congresses around the in detail; however, further reading lists are provided to
world and gradually is distilled down to appear in new guide the reader to additional information. These include
editions of textbooks. There continues to be published an material such as reviews deemed to be of particularly high
increasing number of equine-based textbooks, often quality by chapter authors, as well as selected primary sci-
concentrating on one body system and written from a entific reports and websites.
specialist point of view. Very few have been produced in Patterns of disease can be highly variable between dif-
the last 10 years that specifically address the needs of the ferent geographic regions, and while no book can provide
clinician who is not a full-time equine specialist or the a comprehensive overview of all geographical differences,
equine-interested undergraduate or postgraduate vet- the editors and authors have endeavored to make the
erinary student. This textbook is designed and written chapters in this book useful and relevant to a broad inter-
with these colleagues very much in mind. national audience. It is hoped that in the future this aim
The breadth of content in this book is large, covering a will be enhanced by the translation of the text into several
comprehensive range of topics in equine medicine, of the major languages of the world.
surgery, and reproduction, and it is organized into A unique feature of this book is the inclusion of a large
chapters using a systems-based approach. Each individual number of images, including color photographs, radio-
system is introduced with precise information on the rele- graphic and ultrasound images, and diagrams. Images are
vant basic anatomy and physiology, standard clinical provided for the majority of topics and are intended to
examination techniques, and useful differential diagnostic complement the text on the basis that a ‘picture speaks a
aids. The remainder of the chapter is split up into thousand words’. The inclusion of clinical images can be
diseases and disorders that are pertinent to that system. useful in further understanding the pathogenesis and
The diseases and disorders are grouped together, either pathophysiology of certain conditions, helping the pattern
anatomically or based on presenting clinical signs, into recognition of some diseases and disorders, and visualiz-
sections where specific problems or diseases are presented ing the surgical pathology or procedures that general clini-
in a strict format that is common to the whole book. Thus cians and students rarely see. It is also anticipated that the
each disorder is presented under the individual headings number and quality of images will be a valuable educa-
of definition/overview, etiology/pathophysiology, clinical tional tool for horse owners, enabling veterinarians to
presentation, differential diagnosis, diagnosis, manage- explain more easily certain aspects of disease pathogene-
ment, and prognosis. These systems-based chapters are sis, diagnosis, and management.
complemented by additional chapters on specific areas Finally, it is intended that this textbook, although it
such as behaviorial problems and wounds. The focus is on is large and, hopefully, comprehensive, will not stay gath-
providing clinically relevant information that is required ering dust on a shelf in a practice library or student’s study,
for good case management, but with enough concise infor- but will be in a vehicle with a busy practitioner or on the
mation about etiology and pathophysiology to enable desk of a student, well thumbed and constantly open,
readers to understand the conditions and the rationale for helping educate and assist each individual in his or her
diagnostic and treatment options. Some conditions that daily life. If it does this some of the time, it will have
produce multisystem manifestations may be discussed in achieved its goal.
more than one chapter, with each chapter providing a dif-
ferent emphasis, thereby ensuring a complete overall Graham Munroe
content, but with less duplication. Scott Weese
7
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Abbreviations
AA aplastic anemia CL corpus luteum/corpora lutea
ACB accessory carpal bone CLE cutaneous lupus erythematosus
ACE angiotensin converting enzyme CMA cranial mesenteric artery
ACS autologous conditioned serum CN cranial nerve
ACTH adrenocorticotropic hormone CNS central nervous system
ADAF axial deviation of the aryepiglottic folds COMP cartilage oligomeric protein
ADH antidiuretic hormone COPD chronic obstructive pulmonary disease
AF atrial fibrillation CPII carboxypropeptides of type II collagen
AHF anovulatory hemorrhagic follicle CPE C. perfringensenterotoxin
AHS African horse sickness CPG conjunctival pedicle graft
AI artificial insemination CPK creatinine phosphokinase
AID anemia of inflammatory disease CRF chronic renal failure
ALD angular limb deformitiy CRT capillary refill time
ALDDFT accessory ligament of the deep digital CsA cyclosporine A
flexor tendon CSF cerebrospinal fluid
ALP alkaline phosphatase CSNB congenital stationary night blindness
ALSDFT accessory ligament of the superficial digital CT computed tomography
flexor tendon CTUP combined thickness of uterus and placenta
AM atypical myopathy cTnT/I cardiac troponin T and I
ANA antinuclear antibody CTXs type I collagen C telopeptides
AP alkaline phosphatase CUI chronic uterine infection
APC atrial premature contraction
ARAS ascending reticular activating system D diopter(s)
ARF acute renal failure DCP dynamic compression plate
ASD atrial septal defect DCS dynamic condylar screw (plate)
ASIT allergen-specific immunotherapy DDFT deep digital flexor tendon
AST aspartate aminotransferase DDSL short (deep) distal sesamoidean ligament
AV atrioventricular DDSP dorsal displacement of the soft palate
DHS dynamic hip screw (plate)
BAB blood–aqueous barrier DIC disseminated intravascular coagulation
4-BAD fourth branchial arch defect DIP distal interphalangeal (joint)
BAL bronchoalveolar lavage DIT distal intertarsal (centrodistal) (joint)
BAP bone-specific alklaline phosphatase DJD degenerative joint disease
BCG Bacillus Calmette–Guérin DMSO dimethyl sufoxide
BOB blood–ocular barrier DOD developmental orthopedic disease
bpm beats per minute DP dorsopalmar/plantar
BPV bovine papillomavirus DPJ duodenitis/proximal jejunitis
BSE breeding soundness examination DSP dorsal spinous process
BSP bromsulphalein DSS dioctyl sodium succinate
DV dorsoventral
C1/C2/C3 first/second/third carpal (bone)
CARS compensatory anti-inflammatory response ECE equine coital exanthema
syndrome eCG equine chorionic gonadotropin
CASA computer-assisted sperm motion analysis ECG electrocardiogram/electrocardiography
CBC complete blood count ECR extensor carpi radialis (tendon)
CDI C. difficileinfection EDM equine degenerative myeloencephalopathy
CDE common digital extensor (tendon) EDTA ethylenediaminetetraacetic acid
CEM contagious equine metritis EE eosinophilic enterocolitis
CFT complement fixation test EED early embryonic death
8 CFU colony forming unit EEE Eastern equine encephalitis
CK creatine kinase EGE equine granulocytic ehrlichiosis
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EGS equine grass sickness KCS keratoconjunctivitis sicca
EHM equine herpesvirus myeloencephalopathy
EHV-1 equine herpesvirus-1 L1/2/3/4/5 first/second/third/fourth/fifth stage (larvae)
EIA equine infectious anemia LCP locking compression plate
EIAV equine infectious anemia virus LDE lateral digital extensor (tendon)
EIPH exercise-induced pulmonary hemorrhage LDF lateral digital flexor (tendon)
ELEM equine leukoencephalomalacia LDH lactate dehydrogenase
ELISA enzyme-linked immunosorbent assay LE lupus erythematosus
EMG electromyogram/electromyography LH luteinizing hormone
EMND equine motor neuron disease LMN lower motor neuron
EPF early pregnancy factor LPL long plantar ligament (of the tarsus)
epg eggs per gram LRT lower respiratory tract
EPH equine purpura hemorrhagica LSA lymphosarcoma
EPM equine protozoal myeloencephalitis
ERG electroretinogram/electroretinography MC/MT metacarpal/metatarsal
ERU equine recurrent uveitis MCH mean corpuscular hemoglobin
ESFD external skeletal fixation device MCHC mean corpuscular hemoglobin concentration
ETRs excessive transverse ridges MCP metacarpophalangeal
EVA equine viral arteritis MCV mean corpuscular volume
MDF medial digital flexor (tendon)
FDPs fibrin(ogen) degradation products MDP methyl diphosphonate
FFAs free fatty acids MEED multisystemic eosinophilic epitheliotropic
FFD film focal distance disease
FNA fine-needle aspirate MIA monoiodoacetic acid
FPT failure of passive transfer MMP matrix metalloproteinase
FSH follicle-stimulating hormone MPD myeloproliferative disorder
MPICL medial palmar intercarpal ligament
GABA gamma aminobutyric acid MPV mean platelet volume
GCT granulosa (thecal) cell tumor MRI magnetic resonance imaging
GFR glomerular filtration rate MRLS mare reproductive loss syndrome
GGT gamma-glutamyltransferase α-MSH α-melanophore-stimulating hormone
GI gastrointestinal MTP metatarsophalangeal (joint)
GLDH glutamate dehydrogenase
GnRH gonadotropin-releasing hormone NI neonatal isoerythrolysis
NLS nasolacrimal system
H2 histamine NMD nutritional myodegeneration
hCG human chorionic gonadotropin NSAID nonsteroidal anti-inflammatory drug
HYPP hyperkalemic periodic paralysis
OA osteoarthritis
IAD inflammatory airway disease OAMM occipitoatlantoaxial malformation
ICA iridocorneal angle OC osteocalcin
ICP intracranial pressure OCD osteochondrosis
ICS intercostal space OCLL osseous cyst-like lesions
ICSI intracytoplasmic sperm injection ODSL oblique distal sesamoidean ligament
IFA immunofluorescent antibody (test) OIE World Organization for Animal Health
Ig immunoglobulin OMO open-mouthed oblique
IGF-1 insulin-like growth factor-1 ONH optic nerve head
IL-1 interleukin-1
i/m intramuscular, intramuscularly p/o per os, orally
IMHA immune-mediated hemolytic anemia P1/P2 first/second phalanx
IRAP interleukin receptor antagonist protein PA pyrrolizidine alkaloid
ITP immune-mediated thrombocytopenia PaO2 arterial partial pressure of oxygen
i/v intravenous, intravenously PAL palmar/plantar annular ligament 9
PAS periodic acid–Schiff (stain)