Hair Loss Disorders in Domestic Animals is an in-depth reference on the pathomechanisms and clinical approaches of all skin diseases in domestic animals that have hair loss as the predominant clinical feature. It presents both basic and clinically-relevant knowledge on alopecic disease in animals. This text is a one-of-a-kind resource providing cutting-edge coverage of the physiology and pathology of hair follicles. Disease-specific chapters include: a detailed description of the disease entity, etiology, pathogenesis, clinical and histopathological diagnosis and treatment modalities.

The Editors:

Lars Mecklenburg, DVM, PhD, Cert. Vet. Pathologist, is an independent consultant in veterinary pathology in Hamburg, Germany.

Monika Linek, DVM, DECVD, is Head of the Dermatology Referral Service at Veterinary Specialists of Hamburg in Hamburg, Germany.

Desmond J. Tobin, PhD, FRCPath, FIBiol, is Professor of Cell Biology at the Centre for Skin Sciences, School of Life Sciences, University of Bradford in Bradford, West Yorkshire, Great Britain

Foreword v

Preface vii

Contributors ix

Part 1 Hair Follicle Biology

1.1 Ontogeny of the hair follicle 3
Desmond J. Tobin

1.2 Anatomy and physiology of the hair follicle 17
Desmond J. Tobin

1.3 Hair follicles in domesticated mammals with comparison to laboratory animals and humans 43
Wilfried Meyer

Part 2 How to Approach Alopecic Diseases

2.1 Clinical aspects 65
Monika Linek

2.2 Histopathological aspects 77
Lars Mecklenburg

Part 3 Non-Inflammatory Alopecias

3.1 Congenital alopecia 93
Lars Mecklenburg

3.2 Trichomalacia 115
Lars Mecklenburg

3.3 Disorders of hair follicle cycling 119

3.3.1 Hypothyroidism 119
Monika Linek

3.3.2 Hyperadrenocorticism 132
Rosario Cerundolo

3.3.3 Canine hyperestrogenism 142
Lars Mecklenburg

3.3.4 Canine alopecia X 148
Linda Frank

3.3.5 Canine recurrent flank alopecia 155
Manon Paradis

3.3.6 Telogen effluvium 161
Rosario Cerundolo

3.3.7 Canine postclipping alopecia 163
Rosario Cerundolo

3.3.8 Canine pattern alopecia 164
Manon Paradis

3.3.9 Breed-specific canine hair cycle abnormalities 169
Rosario Cerundolo, Manon Paradis, and Lars Mecklenburg

3.4 Hair follicle dystrophy and atrophy 177
Rosario Cerundolo and Lars Mecklenburg

3.5 Traumatic alopecia 185
Monika Linek

3.6 Scarring alopecia 189
Lars Mecklenburg

Part 4 Inflammatory Alopecias

4.1 Folliculitis with intraluminal organisms 193
Monika Linek

4.2 Eosinophilic folliculitis 215
Monika Linek

4.3 Pustular folliculitis 221
Monika Welle

4.4 Lymphocytic mural folliculitis 227
Monika Welle

4.5 Histiocytic or granulomatous mural folliculitis 243
Monika Welle and Lars Mecklenburg

4.6 Necrotizing mural folliculitis 249
Monika Linek and Lars Mecklenburg

4.7 Alopecia areata 253
Desmond J. Tobin

4.8 Sebaceous adenitis 269
Monika Linek

Index 273