Clinical Anatomy of the Horse Clinical Anatomy of the Horse Page 1 of 3 Clinical Anatomy of the Horse iii Clinical Anatomy of the Horse 1st ed. Hilary M. Clayton, BVMS PhD MRCVS Mary Anne McPhail Dressage Chair in Equine Sports Medicine, College of Veterinary Medicine, Michigan State University, East Lansing MI 48824-1314, USA Peter F. Flood, BVSc MSc PhD MRCVS Professor Emeritus of Veterinary Anatomy, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada Diana S. Rosenstein, DVM, MS, DipACVR Associate Professor of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing MI 48824-1314, USA David Mandeville Division of Media Technology, University of Saskatchewan, 28 Campus Drive, Saskatoon, Saskatchewan, S7N 0X1, Canada 0-7234-3302-X iii iv MOSBY ELSEVIER An affiliate of Elsevier Limited © Elsevier Limited 2005. All rights reserved. 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First edition 2005 ISBN 07234 3302 X British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging in Publication Data Clinical Anatomy of the Horse Page 2 of 3 Clinical Anatomy of the Horse A catalog record for this book is available from the Library of Congress Note Veterinary knowledge and best practice in this field are constantly changing. As new research and experience broaden our knowledge, changes in practice, treatment and drug therapy may become necessary or appropriate. Readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of the practitioner, relying on their own experience and knowledge of the patient, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions. To the fullest extent of the law, neither the publisher nor the authors assume any liability for any injury and/or damage. Commissioning Editor: Joyce Rodenhuis Senior Development Editors: Zoë A Youd, Rita Demetriou-Swanwick Project Manager: Andrew Palfreyman Design Direction: Stewart Larking Printed in China Front Matter iv 1 1 1 Introduction 1 5 2 2 Head 5 25 3 3 Spinal Column 25 35 4 4 Forelimb and Digit 35 65 5 5 Hindlimb 65 89 6 6 Thoracic Viscera 89 97 7 7 Abdominal and Pelvic Viscera Clinical Anatomy of the Horse Page 3 of 3 Clinical Anatomy of the Horse 1 1 Introduction The illustrations in this atlas include photographs of skeletal preparations, dissections and endoscopic views as well as images obtained by radiology, ultrasonography and computerized tomography. These techniques contribute in different but complementary ways to our understanding of the anatomy of the horse (Equus caballus). The atlas is not intended to be a comprehensive anatomical reference book, of which there are several; instead, it is an illuminating companion to these texts. Our intent is to portray those aspects of equine anatomy that are particularly relevant to clinical practice as well as to students of anatomy. Modern photographic and color printing techniques have been used to provide the best possible images of prepared bones and rapidly dissected, unfixed tissues, giving detailed conceptual information that cannot be readily obtained by other means. Some structures, such as the abdominal viscera, deteriorate rapidly in the fresh state, and in these cases we have given high priority to the accurate portrayal of color and texture. Anatomy concerns the form and relationships of the parts of the body. Communication between anatomists is facilitated by the use of agreed standardized terms and a list of these has been developed and periodically revised by the International Committee on Veterinary Anatomical Nomenclature. The list, which forms a small book known as the 1 Nomina Anatomica Veterinaria (NAV), provides general descriptive terms applicable to all vertebrates, and specific terms related to the structure of the horse. During the preparation of the NAV, every effort has been made to maximize conformity between the human and domestic animal nomenclatures, but because veterinary terminology must be based on the normal quadrupedal stance, rather than the erect human position, there are distinct differences in the terms used for direction. The veterinary terms are related to parts of the body, thus blood that flows towards the head is said to be moving cranially and that flowing towards the tail moves caudally. The directional terms are described in detail in this chapter through annotated photographs of a horse. The NAV uses Latin to identify anatomical structures. Anatomists are encouraged to translate the original Latin terms into their own languages unless this leads to obvious ambiguity. In general, anglicized terms have been used in this atlas, though the Latin terms have been retained for most muscles. When a structure has a synonym or well-known name in common usage, it is shown in brackets. 1 1 Introduction Page 1 of 6 Clinical Anatomy of the Horse 1 2 1.1 Live horse, lateral view. Topographic terms. 1 Transverse plane – neck, trunk 2 Dorsal – head, neck, trunk, tail 3 Ventral – head, neck, trunk, tail 4 Rostral – head 5 Caudal – head 6 Cranial – neck, trunk, tail 7 Caudal – neck, trunk, tail 8 Proximal – limb 9 Distal – limb 10 Cranial – proximal limb 11 Caudal – proximal limb 12 Dorsal – carpus and digit 13 Palmar – carpus and digit 14 Dorsal – tarsus and digit 15 Plantar – tarsus and digit 2 1 Introduction Page 2 of 6 Clinical Anatomy of the Horse 2 3 1.2 Live horse, frontal view. Topographic terms. Head, neck, trunk 1 Median plane 1 Introduction Page 3 of 6 Clinical Anatomy of the Horse 2 Sagittal plane 3 Lateral 4 Medial 5 Dorsal plane Limbs 6 Proximal 7 Distal 8 Transverse plane 9 Axial plane 10 Axial 11 Abaxial 12 Cranial 13 Dorsal 3 1 Introduction Page 4 of 6 Clinical Anatomy of the Horse 3 4 1.3 Live horse, caudal view. Topographic terms. Head, neck, trunk 1 Median plane 1 Introduction Page 5 of 6 Clinical Anatomy of the Horse 2 Sagittal plane 3 Medial 4 Lateral 5 Dorsal plane Limbs 6 Proximal 7 Distal 8 Transverse plane 9 Axial plane 10 Axial 11 Abaxial 12 Caudal 13 Plantar 1 Nomina Anatomica Veterinaria (1983, 3rd edition). International Committee on Veterinary Gross Anatomical Nomenclature, Ithaca, New York. 1 Introduction Page 6 of 6 Clinical Anatomy of the Horse 5 2 2 Head In this chapter palpable landmarks are indicated on photographs of live animals, osteological features are shown on bone specimens and radiographs, and soft-tissue structures are revealed using a series of prepared dissections, endoscopic views, radiographs and computed tomographic images. Topographical relationships between the bones and soft-tissue structures are clarified using specimens that have been sectioned in various orientations and accompanying images. 2 Head Page 1 of 68