Pet Owner Educational Atlas
Dermatology Reviewer: Carmen Lorente
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Table of Contents Anatomy of the skin and hair 1 2 3 4
Healthy skin cross-section Hair follicle structure Skin barrier Characteristics of the claw. Trimming technique
Physiopathology of the skin and hair 5 6 7 8 9 10 11 12
Secondary intention healing phases Good versus bad healing Primary lesions Lesions that can be primary and secondary Secondary lesions Disorders of the hair follicle Types of alopecia: inflammatory and non-inflammatory Pruritus characteristics
Medical and surgical treatments 13 14 15 16 17
Types of wounds Types of burns Dressings. Wet healing Procedures to avoid tension on the skin (I). Relaxing incisions Procedures to avoid tension on the skin (II). Suture patterns
Skin pathologies Parasites 18 19 20 21 22 23 24
FAD. Flea allergy dermatitis Tick bites and attachment to the skin Types of scabies (I): Sarcoptes and Notoedres Types of scabies (II): Otodectes and Cheyletiella Types of scabies (III): Demodex Mosquito bites and disease transmission Myiasis larvae
Pet Owner Educational Atlas. Dermatology
Fungi and yeast 25 26 27
Dermatophytosis: Microsporum, Trichophyton and Epidermophyton Cutaneous mycosis Dermatitis caused by Malasseziaw
Infections 28 29 30 31 32 33 34
Pyotraumatic dermatitis, acute moist dermatitis or hot spot Superficial and deep pyoderma Mucocutaneous pyoderma and epitheliotropic lymphoma Sebaceous adenitis Infectious and sterile panniculitis Skin folds (I). Lip fold dermatitis and resolution Skin folds (II). Tail fold dermatitis and resolution
Eyes and ears 35 36 37 38 39 40
Entropion and resolution Ectropion and resolution Healthy ear. Correct cleaning and washing technique External otitis. Ear exudates smears Otitis media and interna Otohaematoma. Types of resolution
Neoplasms 41 42 43 44 45
Nodules. Inflammatory or neoplastic process? Fibrosarcoma and resolution Mastocytoma and metastasis Squamous cell carcinoma Mammary tumour
Miscellany 46 47 48 49 50 51 52 53 54
Frequent disorders of the pads Interdigital fistula caused by a foreign body (spikelet) Pathologies of the anal sacs Dental fistula Foliaceous pemphigus. Autoimmune mechanism Allergies and atopies Anaphylactic reaction. Angioedema Endocrine diseases Seborrheic keratoses disorders
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Anatomy of the skin and hair
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Healthy skin cross-section STRATA: Corneum Granulosum Spinosum Basale
Superficial
Epidermis
Nerve endings
Apocrine gland Hair follicle
Deep
Subcutaneous tissue
Nerve
Cutaneous muscle Artery Vein
Panniculus adipose tissue
Arteriovenous plexus
Middle
Dermis
Sebaceous gland
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Physiopathology of the skin and hair
5 Secondary intention
healing phases 2 Proliferative phase
1 Inflammatory phase
Haemorrhage
Suppuration (pus) Fibrin clot
Neutrophil diapedesis
Arrival of fibroblasts that synthesize collagen
Platelets aggregate Initial vasoconstriction (5-10 minutes)
Phagocytosis cell migration
Posterior vasodilatation and increase of the vascular permeability
Interstitial oedema
3 Remodelling phase
Proliferation of endothelial cells
Granulation tissue formation
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Epithelialization phase
New epidermis
Collagen synthesis and deposit
Migration of epithelial cells over the granulation tissue
Resorption of old collagen Vascular neoformation
Remodelling and contraction of the wound
Connective tissue formation
Bacteria
Erythrocytes
Macrophages
Platelets
Eosinophils
Neutrophils
Fibroblasts
Physiopathology of the skin and hair
7 Primary lesions
Macule Change in colour of the epidermis without altering elevation, consistency or thickness. It may be erythematous and hyper or hypopigmented
Papule Small elevated lesion, erythematous and slightly hardened of up to 1 cm in length caused by cellular infiltration or proliferation
Plaque Elevated lesion, flat, solid and wide of more than 1 cm in length associated to cellular infiltration or proliferation
Pustule Small circumscribed cutaneous elevation that contains purulent material. It may be intraepidermal, subepidermal and follicular
Vesicle Small circumscribed elevation with a collection of clear fluid within the epidermis or below it. It can be intraepidermal or subepidermal
Nodule Solid lesion over 1 cm in diameter, dermal location and usually extended into the deep layers of the skin. It may be of inflammatory or neoplastic origin
Tumour Large mass that can affect any skin structure. It may be of inflammatory or neoplastic origin
Cyst Cavity delimited by an epithelium, which is clinically presented as a nodule or tumour. Desquamative materials or glandular secretions are stored in its interior
Skin wheal Oedematous cutaneous area, raised and irregular that often changes size and shape
Wart Solid elevation of the epidermis with a formation of exophytic projections and generally covered by a scab
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Medical and surgical treatments
15 Dressings. Wet healing Wet secondary intention healing of wounds with dressings 1 Clean the lesion and disinfect the area
2 Shave the hair of surrounding areas
3 Wash the wound thoroughly with saline solution
4 Surgically debride of the wound
exhaustively
under pressure. Remove detritus or contaminating particles
and its edges
5 Apply a bandage with dressings that promote the correct formation of granulation tissue. Monitor the healing
Layers of the dressing Tertiary or retaining layer Secondary or absorbent layer
Wound
Primary or contact layer
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Skin pathologies
20 Tick bites and
attachment to the skin Female tick ingesting blood in order to lay the eggs
Tick head (retractable sucking mouthparts) The tick secretes a substance that attachs its mouthparts into the host’s skin
Palps Chelicerae
Inflammatory skin reaction
Hypostome
The saliva of the tick has an anticoagulant effect and causes a small haemorrhage from which it feeds
The tick inoculates the pathogenic agents during feeding
Skin pathologies
35 Entropion and resolution
Lesions in the cornea of the eye
The edge of the eyelid is folded and is in contact with the cornea
Surgical resolution techniques HOTZ-CELSUS TECHNIQUE Solves the entropion of the lower eyelid
MODIFIED HOTZCELSUS TECHNIQUE: ARROWHEAD Solves the entropion of the lateral edge of the eyelid
FRANS STADES TECHNIQUE Solves the entropion of the upper eyelid
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Skin pathologies
42 Fibrosarcoma
and resolution Surgical removal with wide safety margins Nodule on the withers
Fibrosarcoma is a malignant neoplasm that may appear as a nodule in the skin. Its surgical resolution can be accompanied by radiation therapy
Lateral safety margins
When removing a malignant neoplasm (highly invasive) security surgical margins should be established. As a result, the resulting wound is larger than the tumour but this procedure also reduces the likelihood of recurrence or metastasis
Infiltrative digitations of the neoplasm
Safety margins in depth
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Skin pathologies
47 Interdigital fistula caused
by a foreign body (spikelet) Deep penetration of the spikelet
Location of the spikelet
Course of the fistula
Interdigital inflammation
Spikelet entry point
The veterinary surgeon introduces alligator forceps by the fistulous trajectory to access the spikelet. Sometimes surgery is needed to remove the foreign body and close the fistula
This illustrated work aims at helping veterinary surgeons to communicate with pet owners. In keeping with the previous volume about surgery, the illustrations of this atlas dedicated to dermatology will simplify the explanations given by vets to their clients about the anatomical, physiological and pathological characteristics of skin, as well as those about the diagnostic tests, treatments and surgical techniques that may need to be carried out in some cases. Every illustration was designed to help in the different clinical aspects of the dermatology consultation, from the anatomical and physiological considerations about the skin and its annexes, to the graphic description of infectious, inflammatory, endocrine, allergic or tumoral disease processes which cause dermatological conditions. The clarity and accuracy of the illustrations, designed to make the explanations given to owners easier to understand and less time-consuming, turn this atlas into another useful clinical tool.