Dermatology

Front 1

Give an example of 3 Canine Yeast Infections and where they affect

Back 1

1) Malasezzia pachydermatitis (superficial, skin)
2) Candida albicans (cutaneous/mucous membrane)
3) Cryptococcus neoformans (skin, systemic, rare, severe)

Front 2

What are the 3 groups of Fungi?

Back 2

Yeasts, Filamentous and Dimorphic

Front 3

What is Dermatophytosis?

Back 3

Infection of the hair, claw or stratum corneum with a fungus of the genera:
Microsporum
Trichophyton
Epidermophyton

Front 4

Dermatophytes:
Which species primarily affects cats?
Which species primarily affects cattle?
Which species are adapted for infection of horses?

Back 4

Cats - M. canis
Cattle - T.verrucosum
Horses - T.equinum, M.gypseum, M.canis

Front 5

Describe a Dermatophytosis culture

Back 5

- Use Sabourand's Dextrose Agar (with cycloheximide and chloramphenicol)
- Incabate at 26 degrees for up to 4 wks
- Assess colony plus microscopic features
- Add test medium (phenol red indicator). The dermatophytes utilise protein causing alkaline metabolites and a red colour.
- Early colour change plus white colony suggests dermatophyte

Front 6

How would you treat Dermatophytosis?

Back 6

Usually self-limiting, should treat as zoonotic and reduces enviroment contaimination
- Clip hair around lesion (total body if severe)
- Systemic antifungal (Griseofulvin and Itraconazole)
- Topical therapy to reduce environmental contamination (Enilconazole, Malaseb)
- Monitor treatment with repeat cultures

Front 7

What are the clinical signs of Malassezia Dermatitis?

Back 7

- Pruritus
- Erythema +/- papules
- Scaling
- Greasy Exudation
- Hyperpigmentation/lichenification
- Malodour

Front 8

What are the complications when diagnosing Malassezia Dermatitis?

Back 8

It can mimic or complicate existing disease such as:
- Allergy
- Ectoparasite infestations
- Keratinisation defects

Antibacterial thereapy may also be needed for secondary bacterial infection.

Front 9

How can you assess skin Malassezia populations?

Back 9

Cytology:
- Tape strip
- Direct impression
- Skin Scraping
Culture:
- Swab
- Contact plate
- Detergent scrub

Front 10

How do you treat Malassezia?

Back 10

- Malaseb (2%miconazole, 2% chlorohexidine)
- Systemic ketoconazole is effective but expensive - not licensed in UK

Front 11

Whats the difference between Hyperkeratosis and Hyperplasia?

Back 11

Hyperkeratosis is an increase in the Stratum Corneum (causes a scale)
Hyperplasia is an increase in the Stratum Spinosum (thickening of living cell layer)

Front 12

What is the difference between Folliculitis and Furunculosis?

Back 12

Folliculitis is inflammation of the follicle
Furunculosis is inflammation and destruction of the follicule

Front 13

What is Urticaria?

Back 13

Multiple wheals (hives). Circumscribed raised lesions caused by dermal oedema
Mast Cell = Principle effector cell

Front 14

How would you diagnose and treat Food Hypersensitivity?

Back 14

Diagnose - response to restricted diet and relapse on old diet (intradermal and serological tests virtually useless)
Treat - Allergen avoidance, treat secondary complications, Glucocorticoids if allergen avoidance not possible

Front 15

What is Atopy?

Back 15

- Inherited predisposition for hyper-reactive inflammatory response
- Characterised by specific imunologic abnormalities

Front 16

What is Erythema?

Back 16

Redness or rash of the skin

Front 17

What is Demodecosis and in what species is it common?

Back 17

An inflammatory parasitic skin disease characterised by the presence of larger than normal numbers of demodectic mites.
It is common in the dog, rare in the cat and very rare in horses

Front 18

What is Chorioptic Mange?

Back 18

Common cause of dermatitis in horses, surface feeders, adults survive off host for 70ds, worse in cold weather, feathered horses predisposed, pastern dermatitis

Front 19

What are the different types of Pyoderma?

Back 19

Surface:
- Hot spot
- Intertrigo (skin folds)
- Mucocutaneous pyoderma
- Bacterial overgrowth
Superficial:
- Impetigo (puppies)
- Folliculitis/supf pyoderma
Deep
- Furunculosis
- Acne (chin)
- Bacterial granuloma

Front 20

What is pyotraumatic dermatitis?

Back 20

Hotspot, acute, moist, dermatitis.
can be painful, disruption of stratum corneum, often large breeds, underlying pruritic problem

Front 21

How do you treat pyotraumatic dermatitis?

Back 21

- Topical antibacterial
- Anti-inflammatory depending on severity (topical/systemic glucocorticoids)
- treat/correct underlying causes!!

Front 22

What is impetigo?

Back 22

Pustules in interfollicular epidermis, young dogs are affected, ventral abdomen, often responds to topical therapy alone

Front 23

What is Canine Superficial Pyoderma?

Back 23

Infection of the superficial portion of the hair folliculle
90% pseudintermedius
Often recurrent and pruritic, typically ventral abdomen and trunk

Front 24

How long should you continue to treat pyoderma for?

Back 24

Superficial - approximately 3wks, or 1 week beyond complete clinical cure
Deep - 4-6wks or 2wks beyond complete clinical cure
For both, until underlying trigger has been addressed

Front 25

What should never be used in the treatment of deep pyoderma?

Back 25

Glucocorticoids!!!!

Front 26

How do Pyrethroids work?

Back 26

Insecticide derived from extracts ofd chrysanthemum flowers.
repellant + knockdown effect, pre-synaptic inhibition and inactivation of Na+ channels, hyperexcitation and paralysis, only short time activity, arthropod recovery is possible, light instable - no environmental persistence

Front 27

How do Nicotinoids work?

Back 27

Imidacloprid
Binding to the post synaptic nicotinergic acetylcholine-receptors and thereby causing blockage of the transmission.
Interferes with neural impulse transmission, causes paralysis

Front 28

How do phenylpyrazoles work?

Back 28

Acts on the GABA inhibitory neurotransmitter in the CNS of arthropods. This causes hyperpolarisation of neurons and inhibition of the action potentials. Hyperexcitation and paralysis

Front 29

How do Macrocyclic Lactones work?

Back 29

Affects GABA dependant chlorid-ion channels in cell membranes. Increased permeabiliity of the cell membranes for chlorid ions - flacid paralysis

Front 30

Which kills fleas fastest out of Fipronil (frontline), Selamectin (stronghold), Imidacloprid (advantage) or Nitenpyram (capstar)

Back 30

Nitenpyram - 100% of fleas dead within 3 hrs, all others under 40% dead in 3 hrs

Front 31

When can organophosphates and carbamates be toxic?

Back 31

Amplitude - always body-weight dependant dosification

Front 32

When can pyrethroids be toxic?

Back 32

Acute toxicity in warm bloods low - exception is permethrine in cats!!
Always toxic for bees and fishes

Front 33

When can Amitraz be toxic?

Back 33

Always toxic for fishes
Not to be used in Chihuahuas and cats

Front 34

When can Macrocyclic Lactones be toxic?

Back 34

Ivermectin in collies due to MDR1 mutation - ivermectin enters CNS - effects mammalian GABA Cl channels

Front 35

What are Entomopathogenic fungi and nematodes?

Back 35

Fungi and Nematodes that parasitise insects

Front 36

Which hormones regulate hair growth?

Back 36

Thyroid hormone
Glucocorticoids
Sex Hormones
IGF-1
Prolactin
Melatonin

Front 37

What is hypotrichosis?

Back 37

Either
a) Congenital alopecia
b) Insufficient amount of hair

Front 38

What causes inflammatory alopecia?

Back 38

Folliculitis caused by:
- Infection (common)
- Parasitic (demodex!)
- Bacterial (staphylococci)
- Fungal (dermatophytes)
Sterile Folliculitis is rare

Front 39

What causes non-inflammatory alopecia?

Back 39

Hair follicule structure/function problems
Endocrinopathies
- Coat colour-linked
-Miscellaneous hair cycle/growth problems
- Other (rare)

Front 40

What are the most common causes of alopecia presenting in general practice?

Back 40

1) Traumatic removal of hair
2) Inflammatory (demodecosis, staph folliculitis, dermatophytosis)
3) Malformed/dystrophic/dysplastic or atrophic hair follicules
4) Hair cycle arrest (endocrine)

Front 41

What is a nodule?

Back 41

Round solid elevation of the skin more than 1cm in diameter

Front 42

What is Botryomycosis?

Back 42

Bacterial granuloma (staphylococcal pseudomycetoma). Not fungal! Creates nodules/non-healing wound, may be grains/granules in exudate, site of trauma in some cases

Front 43

What is Phaeohyphomycosis?

Back 43

Dark yeast-like cells, or pseudohyphae and hyphae or any combienation of these.
Cutaneous/subcutaneous/systemic
Usually traumatic implantation - generally low virulence, opportunists

Front 44

What causes Wheals?

Back 44

Inflammtory process:
- Vasoactive mediator release
- Vessel permeability/pressures
- Mast cells often involved
- Allergic and non-allergic mechanisms

Front 45

What is Amyloidosis?

Back 45

A rare dx of skin and URT mucosa:
- Multiple, firm nodules erupt
-5mm to 10cm
- No pain or pruritis
- Biopsy; granulomatous and amyloid
- No effective therapy

Front 46

What are vesicles?

Back 46

Elevations of skin, less than 1cm diamter, contain clear fluid, rare lesions (thin epidermis) transient, progress to ulcers/erosion

Think FMD

Front 47

What are the clinical signs of Feline poxvirus infection?

Back 47

-Small ulcer or cellulitis on face or limb
- 7/10d later widespread lesions
-erythematous nodules
-vesicles, crusts, ulcers
- occasionally pneumonia

Front 48

How would you diagnose and treat Feline Poxvirus Infection?

Back 48

Diagnose
- EM on crusts, virus isolation, serology, histopathology
Therapy
- No specific therapy, resolves in 4-6wks (healthy cats), avoid steroids, hygiene important as zoonosis!

Front 49

What is the most common skin tumour found in dogs?

Back 49

Hepatoid gland adenoma (27%)

Front 50

What is the most common skin tumour found in cats?

Back 50

Basal cell tumour (34%)
then squamous cell carcinoma (23%)

Front 51

What is lichenification?

Back 51

An accentuation of the normal superficial skin markings

Front 52

What is a macule?

Back 52

a flat circumscribed area of change in skin colour <1cm in diameter
(A patch is above 1cm in diameter)

Front 53

What is the difference between Autoimmune disease and Immune-mediated disease?

Back 53

Autoimmune Disease:
An immune response directed against host (self) antigens leading to disease
Immune-mediated disease:
Mediated by immune system, with response directed against self antigens not shown

Front 54

What is Pemphigus Foliaceus?

Back 54

An intradermal pustular disease caused by an autoimmune attack on desmosomes. Causes acantholysis, pustules and crusts. Usually face/neck/feet or whole body

Front 55

What is Pemphigus Vulgaris?

Back 55

Intraepidermal vesicular dermatitis
Very rare, affects mucous membranes and skin, causes erosions and ulcers.
Suprabasilar clefting due to acantholysis

Front 56

What is Dermatophilosis?

Back 56

One of the most important skin infectionis in horses
Caused by dermatophilus congolensis
causes exudate, matted hair, alopecia, paint-brush on the dorsum or limbs
(greasy heal, mud fever, race horses on cannons)

Front 57

What does papillomavirus present as in horses?

Back 57

- Hyperkeratotic Aural plaques
- Concave aspect of the pinnae
- Common in yearling and older - often persist
- Simulium spp is a vector

Front 58

What is Systemic granulomatous disease and chronic eosinophilic enteritis?

Back 58

involves Skin and GIT - grave prognosis (spontainious recovery described). known as equine sarcoidosis "wasting" disease. Aetiology is unknown. Treatment is change feed and systemic GC for months

Front 59

What causes photo-induced.influenced skin disease?

Back 59

Photosensitisation = UV+ poorly pigmented skin + photodynamic agent in skin (e.g. St Johns Wort/liver disease)
Leucocytoclastic vasculitis = nonpigmented lower limbs, acute onset erythema, oozing, crusting, pain, immunosupressive therapy

Front 60

Why are glucocorticoids better at supressing inflammation than NSAIDs?

Back 60

- Suppress T-lymphoctye functions
- Inhibit monocyte-macrophage activities
- Supress fibroblast functions and collagen deposition
- Reduce histamine release from mast cells
- Decreased synthesis of lymphokines (decreased release of proteases)

Front 61

Which species is frontline contraindicated in?

Back 61

Rabbits (lagomorphs)

Front 62

How do you treat ectoparasites in rabbits?

Back 62

Ivermectin weekly for 3 wks
Selamectin

Front 63

How do you treat ectoparasites in Guinea Pigs?

Back 63

Fipronil spray, Selamectin spot on (seleen shampoo)

Front 64

What is Trixacarus Caviae?

Back 64

Guinea pig mange mite.
A burrowing mite, pruritis can be intense, starts on neck/dorsum/trunk, latency period is over a year
Care when handling - convulsions and death reported
Therapy - Ivermectin inj, selamectin spot on, Vit C

Front 65

How can you treat ectoparasites in Ferrets?

Back 65

Fipronil spray, imidacloprid, selamectin, ivermectin inj

Front 66

What are the 4 main lice found on cattle?

Back 66

Bovicola bovis (chewing)
Linognathus vituli (sucking)
Haematopinus eurysternus (sucking)
Solenopotes capillatus (sucking)

Front 67

What is the economic significance of cattle lice?

Back 67

- Small if any effect on liveweight change (some affected more)
- Cause light spot and fleck, a blemish visible on hide of cattle, downgrades value of leather, costs industry 20mil/yr

Front 68

What are the 4 main mites found on cattle?

Back 68

Sarcoptes scabiei (burrowing)
Chorioptes bovis
Demodex bovis
Psoroptes ovis

Front 69

What are the 2 main lice found on sheep?

Back 69

Bovicola ovis (Chewing)
Linognathus ovillus (Sucking)

Front 70

What are the 5 main mites found on sheep?

Back 70

Sarcoptes scabiei
Demodex ovis
Psorobia ovis
Chorioptes bovis
Psoroptes ovis

Front 71

What are the clinical signs of Psoroptic mange (Sheep scab)?

Back 71

- Pustules, then spreading moist lesions
- Fleece becomes matted
- Extreme pruritus
- Can become very extensive
- mites visible with naked eyes, just
- If severe, sheep become thin and may die

Front 72

What is the treament for Sheep Scab?

Back 72

Plunge dipping in OP solution (treatment time must be 1min, heads dipped twice, dip is not heavily fouled, strength must be adequate)
Macrocyclic Lactones by injection

Front 73

Which lice can pigs get?

Back 73

Only haematopinus suis, very large and can transmit african swine fever+swine pox.
Treat with OPs twice at 14d intervals

Front 74

What are the clinical signs of Dermatophilosis in farm animals?

Back 74

Lumpy wool in sheep (rarely affects cattle)
produces crusts of varying thickness on wooled/haired skin
follows wet weather
Lesions painful when lifted
rows of Gr+ cocci (railroad tracks) on smears
Treat by bringing animals out of wet environement, systemic ABs + topical (chlorhexidine scrubs)