Veterinary Allergy

Chiara Noli, Aiden P. Foster, Wayne Rosenkrantz

• Publisher: Wiley-Blackwell
• Year: 2013
• Print ISBN: 9780470672419
• eBook ISBN: 9781118738894
• Edition: 1
• Topic: Medicina
• Subtopic: Medicina veterinaria

The current state of knowledge on this increasingly important subject is beautifully described in this, the first truly comprehensive text of allergic diseases affecting the major veterinary species. It will be an invaluable guide to students, clinicians and researchers alike. From the Foreword by Professor Richard Halliwell, MS, PhD, VetMB, MRCVS, Dip ACVD

Veterinary Allergy is the first comprehensive, high quality reference dealing with all aspects of veterinary allergy in all species and all body systems involved with allergy. Providing solid breadth and excellent depth of coverage, it deals with the immunopathology of the various allergic conditions as well as with clinical presentation, diagnosis and treatment of veterinary allergic diseases.

Key features:

• Broad species coverage, organised by sections on dogs, cats, horses, and other domestic species including large animals, birds and small mammals
• Provides details on diseases affecting the skin, respiratory tract and gut
• Contains practical information for clinicians on management of allergic diseases
• Includes fully-referenced high level detail suitable for specialists and researchers
• Focused on evidence-based medicine and science
• The editors have extensive experience and are respected as world-wide experts in the field
• Every chapter is written by an expert in that particular topic

Anyone seeking information and references on any aspect of allergic conditions in any species should find this book helpful.  The book will be of interest to clinicians in first opinion practice, specialists in veterinary dermatology, gastroenterology, internal medicine, and immunology as well as specialists-in-training in those fields and veterinary students.

The focus on underlying principles and practical clinical aspects is admirable. Immediately useful for practical utilization by practicing clinicians. Dr. Andrew Mackin BSc BVMS MVS DVSc FACVSc DSAM, Diplomate, American College of Veterinary Internal Medicine, Professor and Service Chief, Small Animal Internal Medicine, Dr. Hugh G. Ward Endowed Chair of Small Animal Veterinary Medicine, College of Veterinary Medicine, Mississippi State University, USA

Part 1

Canine Allergy

(Editor: Chiara Noli)

Section 1

Canine Atopic Dermatitis

1

Introduction: canine atopic dermatitis as an evolving, multifactorial disease

Douglas J. DeBoer

Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin–Madison, Madison, WI, USA

Conflict of interest: none declared.

Canine atopic dermatitis (CAD) has been defined as a genetically predisposed, inflammatory and pruritic, allergic skin disease with characteristic clinical features, most commonly associated with IgE antibodies to environmental allergens [1]. However, this rather simplistic definition belies our incomplete understanding of the complex pathogenesis of the disease and its varied clinical features. In fact, as knowledge increases, CAD is increasingly viewed as a clinical description or syndrome, with a variety of manifestations and potential underlying causes that vary from patient to patient.

Historically, the commonly diagnosed skin disease termed ‘eczema’ in humans was recognized as having allergic origins, and as early as the 1930s veterinarians understood that a similar syndrome also existed commonly in dogs [2]. The exact allergens responsible for ‘canine eczema’ were undefined but often were thought to be either food or parasite related, as with fleas in ‘summer eczema’ [3]. In 1941, a physician allergist named F.W. Wittich provided the first description of a dog with seasonal pollen allergy [4], with successful treatment by desensitization via injections of pollen extracts. Subsequent work in dogs focused on respiratory signs associated with pollen allergy and the possible use of dogs as a model for allergic respiratory disease in human beings. Patterson (also a physician allergist) developed a colony of pollen-sensitive dogs in the 1960s, which were reported to have allergic rhinitis and dermatitis [5]. The same dogs could be induced to display asthmatic signs if high concentrations of allergen were introduced into the airways. This emphasis on respiratory signs prompted investigators to deem the disease ‘allergic inhalant dermatitis’, as it was assumed that the dermatitis was caused principally by allergen that entered via the respiratory route. The disease in dogs became known by this name, or sometimes by the more general ‘atopic disease’ or ‘atopy’.

On the human front, by the late 1960s, continuing research on the pathogenesis of ‘eczema’ and allergic respiratory disease was pointing to involvement of a newly described and very different type of immunoglobulin, termed immunoglobulin E (IgE), which was capable of binding to the surface of mast cells. Following exposure to the relevant allergen the IgE induced mast cell degranulation, mediator release, and the familiar inflammatory signs. Though Patterson and colleagues [6] were the first to demonstrate that allergic reactivity could be transferred from a sensitive dog to a normal dog with injections of serum—suggesting mediation by an immunoglobulin—it was Halliwell et al. who made the final connection, publishing a series of papers in the early 1970s confirming the existence of canine IgE, its antigenic relationship to human IgE, its localization in canine skin, and a complete description of canine atopic disease, including detection of allergen-specific IgE in sera of affected dogs [7–10].

It seems that for many years, we were blissfully content to view ‘canine atopy’ as a rather straightforward disorder of the immune system: simply an IgE-mediated, immediate-type hypersensitivity reaction, caused by exposure to environmental allergens via the inhalant route. Students for decades were taught this mechanism as gospel, in spite of many dogs presenting with extreme dermatitis without respiratory signs, reports of human atopic patients with no demonstrable IgE involvement, and ‘classically’ atopic dogs with negative allergy tests. In the 1990s, a new generation of veterinary investigators began to view ‘atopy’ in the light of the explosion in knowledge about the immune system and its complex regulatory mechanisms and to use the more preferred and specific term of ‘canine atopic dermatitis’. The role of cutaneous IgE-bearing antigen presenting cells [11], expression of cytokines by different T-helper lymphocyte populations in the skin [12], and other immunologic details of CAD were uncovered and found to remarkably parallel those of the human atopic disease. From here, a large number of studies extending to the present day have examined such factors as epidermal barrier function and percutaneous allergen penetration as the actual main route of allergen exposure in CAD [13], the important role of skin infections, genetic and environmental influences, and countless other immunologic and molecular details.

The details of these many investigations, and how they fit in the framework of our current understanding, will be the subject of the following chapters in this book. New knowledge about pathogenesis has a direct impact on how we diagnose and treat CAD, and is the basis of new treatments that will arrive on our pharmacy shelves in the future.

In proceeding through these chapters it will be useful for the reader to be aware of some definitions and terminology that describe AD and associated phenomena. This ‘standard terminology’ was originally proposed by the ACVD Task Force on Canine Atopic Dermatitis in 2001 [1] and has been updated since to more accurately express our current understanding [14]. The most common terms that are important to understand, with their current definitions, include the following:

• Atopy. Strictly, a genetically predisposed tendency to develop IgE-mediated allergy to environmental allergens. Atopy is a term originally and literally meaning ‘strange disease’, reflecting the historical lack of understanding of the disease process. It is a general term that in its adjective form atopic can indicate disease of various organ systems, for example atopic rhinitis, atopic asthma, or atopic dermatitis. Though in casual conversation we may refer to a dog as atopic or having atopy, it is important to understand (and to explain to students) that the correct and preferred name for the skin disease in dogs is atopic dermatitis.
• Atopic disease. Any clinical manifestation of atopy. In the dog, atopic dermatitis is the most commonly diagnosed atopic disease. Other, less common atopic diseases include atopic rhinitis, atopic conjunctivitis, etc.
• Atopic dermatitis. A genetically predisposed inflammatory and pruritic allergic skin disease with characteristic clinical features, associated with IgE antibodies most commonly directed against environmental allergens.
• Atopic-like dermatitis. An inflammatory and pruritic skin disease with clinical features identical to those seen in CAD, but in which an IgE response to environmental or other allergens cannot be documented with serological or intradermal methods. From a practical standpoint, this term describes dogs that fit all the clinical criteria for CAD, but who are negative on all allergy tests.

Though these definitions are not perfect and will no doubt be revised again, they represent our best current efforts to describe atopic diseases in dogs in a way that is clinically useful and enables us to establish uniform diagnostic criteria, evaluation schemes and formulate appropriate management plans.

References

1. Olivry T, DeBoer DJ, Griffin CE, et al. The ACVD Task Force on Canine Atopic Dermatitis: forewords and lexicon. Veterinary Immunology and Immunopathology 2001; 81: 143–146.

2. Schnelle GB. Eczema in dogs—an allergy. North American Veterinarian 1933; 14: 37–40.

3. Kissileff A. The dog flea as a causative agent in summer eczema. Journal of the American Veterinary Medical Association 1938; 83: 21–24.

4. Wittich FW. Spontaneous allergy (atopy) in the lower animal. Journal of Allergy 1941; 12: 247–257.

5. Patterson R, Chang WW, Pruzansky JJ. The Northwestern colony of atopic dogs. Journal of Allergy and Clinical Immunology 1963; 34: 455–459.

6. Patterson R, Sparks DB. The passive transfer to normal dogs of skin test reactivity, asthma and anaphylaxis from a dog with spontaneous ragweed pollen hypersensitivity. Journal of Immunology 1962; 88: 262–268.

7. Halliwell REW, Schwartzman RM. Atopic disease in the dog. Veterinary Record 1971; 89: 209–213.

8. Halliwell REW, Schwartzman RM, Rockey LH. Antigenic relationship between human and canine IgE. Clinical and Experimental Immunology 1972; 10: 399–407.

9. Halliwell REW. The localization of IgE in canine skin: an immunofluorescent study. Journal of Immunology 1973; 110: 422–430.

10. Halliwell REW, Kunkle GA. The radioallergosorbent test in the diagnosis of canine atopic disease. Journal of Allergy and Clinical Immunology 1978; 62: 236–244.

11. Olivry T, Moore PF, Affolter VK, et al. Langerhans cell hyperplasia and IgE expression in canine atopic dermatitis. Archives of Dermatological Research 1996; 288: 579–585.

12. Nuttall TJ, Knight PA, McAleese SM, et al. Expression of Th1, Th2 and immunosuppressive cytokine gene transcripts in canine atopic dermatitis. Clinical and Experimental Allergy 2002; 32: 789–795.

13. Marsella R, Nicklin C, Lopez J. Studies on the route of access of allergen exposure in high IgE-producing beagle dogs sensitized to house dust mites. Veterinary Dermatology 2006; 17: 306–312.

14. Halliwell R. Revised nomenclature for veterinary allergy. Veterinary Immunology and Immunopathology 2006; 114: 207–208.

2

Canine immunoglobulin E

Bruce Hammerberg

Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA

Conflict of interest: none declared.

Introduction

The details of the discovery of canine immunoglobulin E (IgE), as recently reviewed [1], illustrate how both canine and human IgE were linked to the most common clinical manifestations of allergic disease more or less simultaneously in the first 70 years of the past century. Atopic dermatitis was described as part of seasonal ‘hay fever’-like signs in a fox terrier in 1941 by a physician [2], on evidence that when serum from this dog was injec...

Table of contents

• Cover
• Dedication
• Title page
• Copyright page
• Acknowledgments
• Contributors
• Foreword
• Introduction: the immunological basis of allergic diseases
• Part 1: Canine Allergy
• Part 2: Feline Allergy
• Part 3: Equine Allergy
• Part 4: Allergy in Other Domestic Species
• Index