Diagnostics and Therapy in Veterinary Dermatology Diagnostics and Therapy in Veterinary Dermatology Edited by Dawn Logas Veterinary Dermatology Center Silver Springs, FL, USA This edition first published 2022 © 2022 John Wiley & Sons, Inc. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by law. Advice on how to obtain permission to reuse material from this title is available at http://www.wiley.com/go/permissions. The right of Dawn Logas to be identified as the author of the editorial material in this work has been asserted in accordance with law. 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Title: Diagnostics and therapy in veterinary dermatology / edited by Dawn Logas. Description: First edition. | Hoboken, NJ : Wiley-Blackwell, [2022] | Includes bibliographical references and index. Identifiers: LCCN 2021043862 (print) | LCCN 2021043863 (ebook) | ISBN 9781119680604 (hardback) | ISBN 9781119680628 (adobe pdf) | ISBN 9781119680635 (epub) Subjects: MESH: Skin Diseases–veterinary | Skin Manifestations Classification: LCC SF901 (print) | LCC SF901 (ebook) | NLM SF 901 | DDC 636.089/65–dc23 LC record available at https://lccn.loc.gov/2021043862 LC ebook record available at https://lccn.loc.gov/2021043863 Cover Design: Wiley Cover Image: © Dawn Logas Set in 9.5/12.5pt STIXTwoText by Straive, Pondicherry, India 10 9 8 7 6 5 4 3 2 1 v Contents Acknowledgments vii Foreword ix List of Contributors xi 1 The Skin as an Immune Organ 1 Domenico Santoro and Megan Boyd 2 How to Get the Most Out of Your Dermatologic History and Examination 9 Michelle Woodward O’Gorman 3 New Diagnostic Tools and Tests for Dermatology 16 Amelia White 4 When, Where, and How to Biopsy Skin 33 Dawn Logas 5 Antimicrobial-Resistant Staphylococcal Infection 39 Christine L. Cain 6 Fungal and Oomycete Infections 50 Darcie Kunder 7 Parasitic Infections 63 Catlin Contreary 8 Emerging Infectious Diseases in Veterinary Dermatology 75 Ana Milena Carmona-Gil 9 Canine Hypersensitivities 86 Rosanna Marsella 10 Feline Hypersensitivities 98 Cecilia Friberg 11 Common and Emerging Autoimmune Diseases 109 Rebekah Westermeyer 12 Endocrine and Metabolic Diseases with Dermatologic Manifestations 128 Katherine Doerr vi Contents 13 Medical Management of Acute and Chronic Otitis 140 Dawn Logas 14 What Is the Difference Between Brand Name, Generic, and Compounded Drugs? 150 Mark G. Papich 15 Topical Therapies 156 Dawn Logas 16 Antimicrobial Resistance 163 Leah D. Blondeau and Joseph M. Blondeau 17 Omega-3 Fatty Acids: What’s New? 175 Dawn Logas 18 Immunopharmacology 180 Domenico Santoro and Megan Boyd 19 Allergen Immunotherapy 193 Natalie Gedon and Ralf Mueller 20 Biologic Therapies for Dermatologic Use 198 Valerie Fadokh 21 Use of Lasers in Dermatology 204 Jason B. Pieper 22 Unconventional and Plant-Based Therapies 212 Dawn Logas 23 Sedation, Anesthesia, and Pain Management in Small Animal Dermatology 218 Luisito S. Pablo 24 How Your Nursing Staff Can Improve Efficiency and Compliance in the Management of Dermatologic Cases 227 Judy Lethbridge 25 Communication Between the Client, Primary Care Practitioner, and Dermatologist 238 JoAnn Stewart 26 The Future of Technology and Computers in Veterinary Medicine 245 Ceara Byrne and Jacob Logas Index 251 vii Acknowledgments First, I want to thank Gail Kunkle and Richard Halliwell for all their love and support over the years. I love you guys for their support and mentorship that got me started in der- more than you will ever know. Finally, I want to thank my matology. Second, I want to thank my clients and patients best friend and business partner, Marcia Schwassmann, for over the last 35 years who have taught me so much about making me a better person and veterinarian along with dermatology that I did not know before. Next, I want to helping me edit this book. thank my husband, Paul, and sons, Christopher and Jacob, Dawn Logas ix F oreword Dear Colleague climate change and issues such as antibiotic resistance, This book is not meant to be an all-i nclusive dermatology which are not found in other currently available dermatol- text. It is meant to help you understand how dermatolo- ogy texts. As veterinarians we will become more important gists think and what we feel is important when working up in the One Health movement as infectious diseases spread our cases, so you can improve how you work up your own to new areas and antibiotic resistance continues to spread. dermatology cases. It will also hopefully improve the use of I want to thank the authors who contributed to this book our veterinary nurses and the communication between for their hard work and diligence in delivering practical the primary care veterinarian and the dermatologist. chapters with information that primary care veterinarians Furthermore, I have included information in this book can use every day. about diseases whose incidences are increasing because of Dawn Logas xi List of Contributors Joseph M. Blondeau, BSc, MSc, PhD Dawn Logas, DVM, DACVD Royal University Hospital and University of Veterinary Dermatology Center, Maitland, FL, USA Saskatchewan, Saskatoon, Saskatchewan, Canada Jacob Logas, MS CS Georgia Tech, PhD Leah D. Blondeau, PhD Georgia Institute of Technology School of Interactive Royal University Hospital and University of Computing, Atlanta, GA, USA Saskatchewan, Saskatoon, Saskatchewan, Canada Rosanna Marsella, DVM, DACVD Megan Boyd, DVM, DACVD University of Florida, Gainesville, FL, USA Animal Dermatology Center, Studio City, CA, USA Ralf Mueller, DVM, MANZCVSc (Canine Medicine), DACVD, Ceara Byrne, MS CS Georgia Tech, PhD FANZCVSc (Dermatology), DECVD Georgia Institute of Technology School of Interactive Centre for Clinical Veterinary Medicine, LMU Munich, Computing, Atlanta, GA, USA Germany Christine L. Cain, DVM, DACVD Luisito S. Pablo, DVM, MS, DACVAA School of Veterinary Medicine, University of College of Veterinary Medicine, University of Florida, Pennsylvania, Philadelphia, PA, USA Gainesville, FL, USA Ana Milena Carmona- Gil, DVM, MSc Mark G. Papich, DVM DermaVet Centro de Dermatología Veterinaria, Medellín, North Carolina State University, Raleigh, NC, USA Antioquia, Colombia Jason B. Pieper, DVM, MS, DACVD Catlin Contreary, DVM, DACVD Iowa State University, Ames, IA, USA Veterinary Dermatology Center, Maitland, FL, USA Domenico Santoro, DVM, MS, DrSc, PhD, DACVD, DECVD, Katherine Doerr, DVM, DACVD DACVM (Bacteriology, Mycology, Immunology) Veterinary Dermatology Center, Maitland, FL, USA University of Florida, Gainesville, FL, USA Valerie Fadok, DVM, DACVD, PhD JoAnn Stewart, RVT, CVPM, CCFP Zoetis, Bellaire, TX, USA Executive Director, Collaborative Care Coalition, Gurnee, IL, USA Cecilia Friberg, DVM, DACVD Sodra Djursjukhuset, Stockholm, Sweden Rebekah Westermeyer, BSEd, DVM, DACVD, MRCVS Animal Allergy Specialists, Oahu, HI, USA Natalie Gedon, DVM Asia Veterinary Diagnostics, Kowloon, Hong Kong University of North Carolina College of Veterinary Medicine, Raleigh, NC, USA Amelia White, DVM, MS, DACVD Auburn University College of Veterinary Medicine, Darcie Kunder, VMD, DACVD Auburn, AL, USA Friendship Hospital for Animals, Washington, DC, USA Michelle Woodward O’Gorman, DVM, DACVD Judy Lethbridge, RVT (registered veterinary technician) Baton Rouge Veterinary Specialists, Baton Rouge, Veterinary Dermatology Center, Maitland, FL, USA LA, USA 1 1 The Skin as an Immune Organ Domenico Santoro and Megan Boyd KEY POINTS ● The skin is an extremely active immunologic organ. ● The skin has many resident immunologically active cells. ● The skin defense system includes a physical barrier (stratum corneum and hair), a chemical barrier (fatty acids and antimicrobial peptides), an immunologic barrier (innate and adaptive immune system), and a microbiological barrier (beneficial microorganisms). ● Keratinocytes are the most immunologically active cells in the epidermis. ● The skin is commonly affected by immune system disorders. The skin is the largest organ in the body. It has long When pathogenic microorganisms breach the physical been known as the primary physical barrier between an and chemical defenses of the skin, they activate the skin- organism and its environment, but since the early 1980s associated lymphoid tissue (SALT) (Table 1.1). SALT the skin has been recognized as an active immune includes dendritic cells, mast cells, lymphocytes, and organ with its own skin- associated immune system. keratinocytes, and forms part of the innate immune system The skin’s defense system consists of physical, chemi- (Figure 1.1). Innate immunity, which is considered the cal, immunologic, and microbiologic components that most ancient branch of the body’s immune defenses, is protect the body against trauma, chemicals, toxins, and characterized by a rapid onset of action (minutes to hours), microorganisms. a lack of specificity (it recognizes common microbial struc- The physical barrier represents the first line of defense tures as opposed to specific organisms), and a lack of mem- against invaders. It is composed of keratinocytes tightly ory, which means the response does not improve with each bonded together by a lipid- rich mortar in the stratum cor- exposure. Cells of the innate immune system include mac- neum (top layers) and keratinocytes joined together by rophages, dendritic cells, neutrophils, natural killer (NK) tight cell- to- cell junctions in the lower layers. The chemical cells, mast cells, and keratinocytes. When innate immunity barrier consists of compounds with active antimicrobial is overwhelmed, the adaptive branch of the immune sys- activity, including fatty acids and antimicrobial or host tem (Figure 1.2), primarily made of T and B lymphocytes, defense peptides secreted by sebaceous glands and is activated. The adaptive immune response is character- keratinocytes. If the physical and chemical defenses of the ized by a slow onset of action (days to weeks), high speci- skin are overcome by invaders, components of the innate ficity (recognizes unique antigens), and memory, which and active immune system along with beneficial microor- means the speed and magnitude of the response improve ganisms in the skin microbiome become important. with each exposure. The innate and adaptive branches of Beneficial microorganisms compete for the same niche as the immune system are highly interconnected. When cells pathogens and actively secrete antimicrobial peptides of the innate immune system are activated, they secrete (AMPs) that inhibit the proliferation of pathogenic numerous inflammatory cytokines and chemokines that competitors. prime and direct the adaptive immune system’s response. Diagnostics and Therapy in Veterinary Dermatology, First Edition. Edited by Dawn Logas. © 2022 John Wiley & Sons, Inc. Published 2022 by John Wiley & Sons, Inc. Table 1.1 Cells of the innate and adaptive immune system discussed in this chapter. Cell type Functions Location Cytokines produced Expressed molecules Innate Keratinocyte Mechanical barrier, epidermal Epidermis IL- 1, IL- 6, TNF, IL- 8, IL- 10, IL- 12, IL- 15, TLR, MHC- I, MHC- II, AMP production IL- 18, IL- 19, IL- 20, TGF, IL- 20, IL- 23, Immune function GM- CSF, G- CSF Langerhans cell Antigen- presenting cell Epidermis IL- 12, IL- 23, IL- 6, TNF Fc and mannose receptors, ICAM- 1, IL- 12, MHC- II Dermal dendritic cell Antigen- presenting cell Dermis IL- 12, IL- 23, IL- 6, TNF Fc and mannose receptors, ICAM- 1, IL- 12, MHC- II Mast cell Hypersensitivity reactions, Dermis TNF, IL- 1, IL- 4, IL- 5, IL- 6, IL- 13, CCL3, TLRs, NF- kB, NFAT, AP- 1 vasodilation, chemotaxis, CCL4, IL- 3, GM- CSF inflammation Eosinophil Hypersensitivity reactions, Dermis IL- 3, IL- 5, IL- 8, IL- 10, leukotrienes, Fc receptor vasodilation, chemotaxis, GM- CSF, hydrolases inflammation Neutrophil Innate immunity, phagocytosis Dermis ROS, proteolytic enzymes TLRs, lectin receptor, mannose receptor M1 macrophage Phagocytosis, antigen presentation, Dermis IL- 6, IL- 12, TNF, iNOS JAK1, JAK2, STAT1, bactericidal activity STAT2 M2 macrophage Phagocytosis, antigen presentation, Dermis IL- 10, TGF, arginase- 1 JAK1, JAK2, JAK3, STAT6 regenerative effects ILC (Innate lymphoid Innate immunity Dermis IL- 1, IL- 23, IL- 25, IL- 33, TSLP Id2, T- bet, GATA 3, ROR cell) Both innate γ/δ T cell Elimination of intracellular Dermis IL- 17, IFN MHC- I and microorganisms and infected cells; adaptive cell death Natural killer cell Innate immunity against viruses and Dermis IFN, GM- CSF, IL- 3 MHC- I intracellular bacteria Natural killer T cell Elimination of lipid antigens Dermis IL- 4, IL- 17, IL- 22, IFN MHC- 1 Adaptive B lymphocyte Humoral response Dermis IL- 2, IL- 4, IL- 6, IL- 11, IL- 13, TNF, BAFF Antibodies T- helper lymphocyte Coordinates immune function Dermis Various depending on the type of T- helper cell Various depending on the type of T- helper cell T- cytotoxic lymphocyte Elimination of intracellular Dermis IFN Perforin, granzyme, granulysin microorganisms and infected cells T- regulatory Control of immune response Dermis IL- 10, TGF FoxP3, STAT5 lymphocytes Key: AMP, antimicrobial peptides; AP, activator protein; BAFF, B- cell activating factor; CCL, chemokine ligand; FoxP3, forkhead box P3 protein; GATA, transcription factor; G- CSF, granulocyte colony- stimulating factor; GM- CSF, granulocyte macrophage colony- stimulating factor; ICAM, intercellular adhesion molecule; Id2, DNA binding protein inhibitor 2; IFN, interferon; IL, interleukin; iNOS, inducible nitric oxide synthase; JAK, Janus kinase; MHC, major histocompatibility complex; NFAT, nuclear factor of activated T cell; NF- kB, nuclear factor kappa B; ROR, retinoic acid- related orphan receptors; ROS, reactive oxygen species; STAT, signal transducer and activator of transcription; T- bet, T box transcription factor; TGF, transforming growth factor; TLR, Toll- like receptor; TNF, tumor necrosis factor; TSLP, thymic stromal lymphopoietin. 0005172709.INDD 2 09-27-2021 10:32:17