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Small Animal Oncology Small Animal Oncology Joanna Morris Formerly of Department of Clinical Veterinary Medicine, University of Cambridge Veterinary School and Jane Dobson Department of Clinical Veterinary Medicine, University of Cambridge Veterinary School Small Animal Oncology Small Animal Oncology Joanna Morris Formerly of Department of Clinical Veterinary Medicine, University of Cambridge Veterinary School and Jane Dobson Department of Clinical Veterinary Medicine, University of Cambridge Veterinary School © 2001 distributors Blackwell Science Ltd Marston Book Services Ltd Editorial Offices: PO Box 269 Osney Mead, Oxford OX2 0EL Abingdon 25 John Street, London WC1N 2BS Oxon OX14 4YN 23 Ainslie Place, Edinburgh EH3 6AJ (Orders: Tel: 01235 465500 350 Main Street, Malden Fax: 01235 465555) MA 02148 5018, USA 54 University Street, Carlton USA and Canada Victoria 3053, Australia Iowa State University Press 10, rue Casimir Delavigne A Blackwell Science Company 75006 Paris, France 2121 S. State Avenue Ames, Iowa 50014-8300 Other Editorial Offices: (Orders: Tel: 800-862-6657 Fax: 515-292-3348 Blackwell Wissenschafts-Verlag GmbH Web www.isupress.com Kurfürstendamm 57 email:[email protected]) 10707 Berlin, Germany Australia Blackwell Science KK Blackwell Science Pty Ltd MG Kodenmacho Building 54 University Street 7–10 Kodenmacho Nihombashi Carlton, Victoria 3053 Chuo-ku, Tokyo 104, Japan (Orders: Tel: 03 9347 0300 Fax: 03 9347 5001) Iowa State University Press A Blackwell Science Company A catalogue record for this title 2121 S. State Avenue is available from the British Library Ames, Iowa 50014-8300, USA ISBN 0-632-05282-1 The right of the Authors to be identified as the Authors of this Work has been asserted in Library of Congress accordance with the Copyright, Designs and Cataloging-in-Publication Data Patents Act 1988. Morris, Joanna. Small animal oncology/Joanna Morris and Jane All rights reserved. No part of Dobson. this publication may be reproduced, p. cm. stored in a retrieval system, or Includes bibliographical references (p.). transmitted, in any form or by any ISNB 0-632-05282-1 (pb) means, electronic, mechanical, 1. Dogs – Diseases. 2. Cats – Diseases. photocopying, recording or otherwise, 3. Veterinary oncology. I. Dobson, Jane M. except as permitted by the UK II. Title. Copyright, Designs and Patents Act SF992.C35 M65 2000 1988, without the prior permission 636.089 6992 – dc21 00-058599 of the publisher. ¢ For further information on First published 2001 Blackwell Science, visit our website: www.blackwell-science.com Set in 9.5 on 11.5 pt Times by Best-set Typesetter Ltd., Hong Kong Printed and bound in Great Britain at the Alder Press Ltd, Oxford and Northampton The Blackwell Science logo is a trade mark of Blackwell Science Ltd, registered at the United Kingdom Trade Marks Registry Contents Acknowledgements vi Disclaimer vi Introduction 1 1. Pathogenesis and Tumour Biology 4 2. Diagnosis and Staging 15 3. Treatment Options 31 4. Skin 50 5. Soft Tissues 69 6. Skeletal System 78 7. Head and Neck 94 8. Gastro-intestinal Tract 125 9. Respiratory Tract 144 10. Urinary Tract 154 11. Genital Tract 166 12. Mammary Gland 184 13. Nervous System 192 14. Endocrine System 204 15. Haematopoietic System 228 16. The Eye and Orbit 252 17. Miscellaneous Tumours 262 Appendices 279 I General Reading List 279 II Actions, Indications and Toxicity of Cytotoxic Agents used in Veterinary Practice 280 III Bodyweight: Surface Area Conversions 284 IV Protocols for Administration of Doxorubicin and Cisplatin 285 V Glossary of Drugs and Dosages Included in Text 286 Index 292 Please note: the plate section falls between pp. 162 and 163 v Acknowledgements The authors gratefully acknowledge the help and acknowledge the artistic skills of John Fuller who support of friends, families and colleagues in the was responsible for the original line drawings writing and production of this book. reproduced in this book. In particular we would like to thank David We are also grateful to Dr Davina Anderson for Bostock, Phil Nicholls, Elizabeth Villiers, Kathleen her help in reading the text and advice on surgical Tennant, Andy Jefferies, Mike Herrtage, Malcolm matters, Malcolm Brearley for his help with Brearley, Ruth Dennis, Dick White and the Radiol- Chapter 13, Nervous System, Dr David Williams, ogy Department, Queens Veterinary School Hospi- Chapter 16, on the eye, and Mike Herrtage, Chapter tal, Cambridge, for contributing many of the 14, Endocrine System. pictures used to illustrate the text. We should also DISCLAIMER The authors have made every effort to ensure that The cytotoxic drugs detailed in this book are not therapeutic recommendations particularly concern- licensed for veterinary use. All of these agents are ing drug selection and dosage set out in the text are potentially hazardous to the patient and to persons in accord with current recommendations and prac- handling or administering them. Veterinary sur- tice. However, in view of ongoing research, changes geons who prescribe such drugs to patients in their in government regulations and the constant flow of care must assume responsibility for their use and information relating to drug therapy and drug reac- safe handling. Veterinary surgeons who are not tions, the reader is urged to check the drug manu- familiar with the use of cytotoxic agents should facturer’s instructions for any added warnings and seek further information and advice from a veteri- precautions. nary oncologist. vi Introduction Neoplasia is a common problem in small animal most common sites for cancer in this study. In the veterinary practice.As facilities in general practices UK study, the three most common tumour types improve and more investigations are conducted were benign. Canine cutaneous histiocytoma pre- into the cause of dog and cat illnesses, it is being dominated, followed by lipoma and adenoma. Mast increasingly diagnosed. Although accurate figures cell tumour and lymphoma were the next most on the incidence of tumours in cats and dogs are common tumour types (Fig. I.2). lacking, conservative estimates suggest that one in Comparable up-to-date epidemiological figures ten cats or dogs will develop a tumour during their are not available for cats in the UK. In other natural life. A few epidemiological studies on small surveys, lymphoma and other haematopoietic animal cancer do exist but most of these refer to tumours are the most common tumour types and dogs. In the USA, a post mortem study on 2000 are much more frequent than in the dog. Although dogs revealed that cancer was the most common skin and soft tissue tumours are important in the cause of death, with 23% of animals dying from the cat, malignant neoplasms such as squamous cell car- disease (Bronson 1982). In a more recent study cinoma and soft tissue sarcoma are probably more based on questionnaire responses in the UK, 16% frequent than benign lesions. Mammary tumours of dogs died from cancer (Michell 1999). Cancer are less frequent in the cat, but a greater propor- was the most frequently recognised cause of death tion are malignant. in both male and female dogs, but in neutered The demand for treatment of pets with cancer is males heart disease was of equal importance. increasing and seems likely to do so for the fore- Another recently conducted study on the inci- seeable future as more animals become insured and dence of tumours in a population of insured dogs their treatment costs are covered. Conventional in the UK has provided up-to-date information on methods for cancer therapy in animals, as in the distribution of tumour types (Samuel et al. humans, are surgery, radiotherapy and chemo- 1999). The skin and soft tissues were found to be therapy. These techniques, however, need not be the most common sites for tumour development, used in isolation. Indeed, as our understanding of followed by mammary gland, haematopoietic the biology of cancer has increased, it has become tissues (including lymphoid), urogenital system, clear that combining surgical management of a endocrine organs, alimentary system and orophar- primary mass with chemotherapy directed at sys- ynx (Fig. I.1). These results are similar to those temic disease, is the most logical and potentially reported by Dorn and others (Dorn et al. 1968a, b) effective way of managing malignant tumours. in California who used diagnosis of neoplasia in Fears of the side-effects associated with cancer veterinary practices in specified areas of the treatment in pet animals are not well founded since country combined with histological examination in most are drawn from comparisons with human a central laboratory and a probability survey to cal- cancer therapy where the aim of treatment is to culate the population at risk. The skin, mammary prolong life at all costs. The management of animal gland and haematopoietic tissues were the three cancer also seeks to prolong lifespan but aims to 1 2 Small Animal Oncology Fig. I.1 Standardised incidence rates for main tumour sites (per 100000 dogs/year). achieve a good quality of life as well. All treatment out by a referral centre. Practical details of modalities are adjusted to achieve this aim and if chemotherapy and guidance on safety, however, are any patient is deemed to be suffering, treatment can given, since an increasing number of general prac- be stopped or the animal euthanased. tices are using cytotoxic drugs and it is essential that The purpose of this book is to provide a basic stringent handling practice is adhered to. Again, clinical approach to the diagnosis and treatment of more detailed texts exist and specialist help is avail- the more common tumours in cats and dogs for able at a referral centre.Although, at present, Cam- the practising veterinary surgeon, undergraduate bridge University has the only radiotherapy unit in student and veterinary nurse. It is not intended to the UK dedicated to small animal use, radiotherapy be a comprehensive reference textbook, covering is covered in some detail since it is helpful for all aspects of veterinary oncology, since several general practitioners to be aware of the aims of such texts exist (see general reading list in Appen- treatment and the tumour types which are suitable dix I).
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