Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Equine Med and Surgery II > Lecture 12: Approach to Equine Dermatoses > Flashcards

Lecture 12: Approach to Equine Dermatoses Flashcards

1
Q

What are the most common causes of pruritus

A
  1. Ectoparasites- culicoides, horn and stable flies, chorioptes
  2. Allergies-atopic dermatitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are some pruritic lesions

A

alopecia, papules, pustules, urticaria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is alopecia

A

traumatic hair loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what causes papules

A

ectoparasites, infectious, allergies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what causes pustules

A

infectious

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what causes urticaria

A

allergies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what ectoparasites cause diffuse ventral midline vs focal ventral midline pruritus

A

diffuse ventral midline: culicoides
Focal ventral midline: horn and stable flies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what ectoparasite pruritic lesions on mane and tail

A

culicoides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what ectoparasite causes pruritic lesions on the pastern

A

chorioptic mange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

t or f: culicoides gnats are small, weak fliers

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where do culicoides gnats lay their eggs

A

damp marshy areas- decaying vegetation and mature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

culicoides gnats are blood sucking: what attracts the host

A

C02, lactic acid, octenol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the vector for onchocera cervicalis

A

culicoides gnats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the preferred feeding sites for culicoides gnats

A

top line: ears, mane, back and tail
Ventrum: diffuse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what doe the bites of culicoides cause

A

painful, pruritic lesions, develop into papules and wheals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is a common presentation for culicoides gnats

A

rubbing mane and tail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what ectoparasite could cause this presentation of attacking mane, tail and diffuse on ventrum

A

culicoides gnats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is tx for culicoides gnats

A
  1. Reduce population- remove manure and decaying vegetation, remove standing water
  2. Gnat traps- body temperature, contain octanol
  3. Reduce exposure- body suits, fans, ultra-fine screens, stable at night, repellents
  4. Prednisone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

repellents containing __ are good for treating culicoides gnats

A

permethrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

horn flies have a large population during what time of year

A

summer months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

T or f: horn flies are strong fliers

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

where do horn flies like to lay their eggs

A

cow manure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what do horn flies vector

A

protozoal disease, helminths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are the preferred feeding sites for horn flies

A
  1. Ventrum in warm sunny weather, focal
  2. Top line- rainy or cool weather
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

t or f: adult horn flies rarely leave host

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is the presentation of horn fly bites

A

painful, pruritic, papules and wheals (central crust), focal and central midline dermatitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is the most common horn fly species in U.S.

A

H. Irritans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is tx for horn flies

A
  1. Reduce population- remove decaying vegatation and manure, limit access to cattle- removal of cow manure disrupts life cycle
  2. Reduce exposure- repellents, fly predators
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Horn flies are resistant to what type of repellents

A

pyrethroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

t or f: stable flies are large flies that resemble house flies

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

where doe stable flies like to lay their eggs

A

wet straw, bedding or manure (aging manure more attractive)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

stable flies life cycle is __dependent

A

temperature dependent (4 weeks in warm weather)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

stable flies are blood sucking and rest after meal and can be found where (vs horn flies that don’t leave host)

A

barn wall, fence, other structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what do stable flies vector

A

viral disease, protozoal disease, helminths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what are the preferred feeding sites for stable flies

A

neck, back, chest, groin, legs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what are the presentation of bites from stable flies

A

painful, pruritic, papules and wheals (central crust), insect hypersensitivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

owner noticed many large flies biting horses- based on the location of neck and legs- what are the likely flies

A

stable flies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what is tx for stable flies

A
  1. Reduce population- remove moist bedding twice weekly
  2. Reduce exposure- repellents, fly predators
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what is this?

A

chorioptes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what are chorioptes

A

surface mites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what do chorioptes feed on

A

epidermal debris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

How Is chorioptes transmitted

A

direct and indirect (fomites) contact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

chorioptes have larger populations and are more severe during what time of year

A

colder weather/winter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

hot and dry conditions __survival of chorioptes

A

decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what are the most common locations for chorioptes lesions

A

feather fetlocks in draft horses, fetlocks, pastern, tail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

based on the location of these lesions what could have caused this

A

chorioptes- feather fetlocks, pastern, tail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

how do you dx chorioptes

A

hx, skin scrape (use insecticide), biopsy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

what are the topical tx for chorioptes

A

lime sulfur, fipronil (front line spray), bravecto locally on pastern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

what are the systemic tx for chorioptes

A

ivermectin, moxidectin, doramectin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

what is atopic dermatitis

A

allergic reaction to environmental antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

what type of hypersensitivity reaction is atopic dermatitis

A

1 and 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

what Ig’s are present in atopic dermatitis

A

IgE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What are the routes of exposure for atopic dermatitis

A

percutaneous, respiratory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

what is the classic presentation for atopic dermatitis

A

age 9.5 years, seasonal, pruritus, urticaria (biggest sign), on face, pinnate, ventral thorax/abdomen, legs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

wha is the biggest sign of atopic dermatitis

A

urticaria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

what things do horses do that indicate atopic dermatitis

A

biting at themselves, rubbing, stomping feet, flick tails, shake head

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

what type of lesions are associated with atopic dermatitis

A

excoriations, self induced alopecia, lichenification, hyperpigmentation, secondary infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

based on this presentation- what is likely problem

A

atopic dermatitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

How do you dx atopic dermatitis

A

Hx, clinical signs, rule out ectoparasites, contact dermatitis, drug reaction, urticaria and angioedema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What type of testing can you do for atopic dermatitis

A
  1. Intradermal allergy testing
  2. Serology testing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

what are some topical tx for atopic dermatitis

A
  1. Shampoos and rinses0 remove allergens and eliminate dry skin
  2. Anti pruritic agents: colloidal oatmeal, pramoxine, glucocorticoids (hydrocortisone shampoo)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

what are some systemic tx for atopic dermatitis

A
  1. Hydroxyzine pamoate
  2. Doxepin
  3. Prednisolone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

what are the most common causes of alopecia

A
  1. Infectious- dermatophytosis, pyoderma (staph)
  2. Follicular disease- alopecia areata
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

what is the most common dermatophyte in horses

A

trichophyton equinum

65
Q

what are the signs of dermatophytosis

A

alopecia- centrifugal ring pattern, crusts, erythema, papules

Hooves weak/splitting
+/- pruritus

66
Q

where are common locations for dermatophytosis lesions

A

areas of tack, coronary band, face, neck, dorsal lateral thorax/girth, legs

67
Q

what is the most likely cause of these lesions

A

dermatophytosis

68
Q

what is the most likely cause of these lesions

A

dermatophytosis

69
Q

t or f: woods lamp is a very helpful dx for dermatophytosis in horses

70
Q

how do you dx dermatophytosis

A
  1. Trichogram
  2. DTM add vitamin B
  3. Biopsy
71
Q

T or f: dermatophytosis may spontaneously regress in 3 months in healthy horses

72
Q

what are some topical tx for dermatophytosis

A
  1. Miconazole and chlorhexidine
  2. Ketoconazole and chlorhexidine
  3. 2% lime sulfur
73
Q

what are some systemic tx for dermatophytosis

A
  1. Griseofulvin
  2. Fluconazole
  3. Terbinafine
74
Q

what is the most common cause of pyoderma in horses

75
Q

Folliculitis is associated with __pyoderma

A

superficial

76
Q

furunculosis is associated with __pyoderma

77
Q

what are some clinical signs of pyoderma

A

circular alopecia-epidermal collarettes, crusts, papules, draining tracts, pruritus

78
Q

what is the most common location for staph pyoderma

A

saddle, lumbar, pastern (especially pastern)

79
Q

What is likely cause of these lesions. You performed a cytology and ruled out dermatophytosis

A

Pyoderma- likely staph

80
Q

What is likely cause of these lesions

A

pyoderma- likely staph

81
Q

what are some risk factors for developing staphylococcal pyoderma- MRSA

A

ceftiofur or aminoglycosides, large farm size, previous colonization or infection of other horses on farm, previous admission to vet hospital

82
Q

how do you dx staphylococcal pyoderma

A
  1. Culture and biopsy- if no response to empirical antibiotics
83
Q

what sign is indicative of deep pyoderma

A

draining tracts

84
Q

what is tx of staphylococcal pyoderma

A

TMS, enrofloxacin, doxycycline, topical therapy

85
Q

what is alopecia areata

A

follicular disease, non-scarring, non-inflammatory alopecia

86
Q

in alopecia areata __ and __ directed against anagen hair follicles

A

lymphocytes and antibodies

87
Q

what breeds are at risk for alopecia areata

A

appaloosas, palominos

88
Q

t or f: alopecia areata has no pruritus and is non-painful

89
Q

what lesions are associated with alopecia areata

A

focal or diffuse lesions, may spare mane and tail
On face, neck and trunk

90
Q

what is likely cause of these lesions- you noted no crusting, no inflammation, no scales and are non-painful

A

alopecia areata

91
Q

how do you dx alopecia areata

A
  1. Rule out
  2. Biopsy and histopath- peribulbar accumulation of lymphocytes, “swarm of bees”
92
Q

Appaloosas presents with skin lesions they are non-inflammatory, no crusts or scales noted and are non-painful. The following histopath was taken- what do you notice and what is likely dx

A

Follicle in anagen, lymphocytes around follicle

Dx: alopecia areata

93
Q

what is tx for alopecia areata

A

no curative tx, corticosteroids may help

94
Q

what are the differential diseases for scaling and crusting dermatoses

A
  1. Infection- dermatophilus congolensis
  2. Immune mediated: pemphigus foliaceous, sarcoidosis
  3. Keratinization defect: seborrhea
95
Q

what is the cause of dermatophilosis

A

dermatophilus congolensis

96
Q

what is the survival of dermatophilus congolensis dependent on

A

type of soil, water content

97
Q

horse presents with crusting lesions, the following histo was taken- what is cause

A

dermatophilus congolensis

98
Q

what is the pathogenesis of dermatophilosis

A
  1. Skin damage
  2. Moisture- causes release of infective, motile, flagellated zoospore
99
Q

what is the most common bacterial skin disease in large animals

A

dermatophilosis

100
Q

dermatophilosis is more prevalent in what climates

A

humid, heavy rainfall

101
Q

t or f: dermatophilosis is contagious

102
Q

what are the 4 distributions of dermatophilosis

A
  1. Rump and dorsum- run off, dribbling pattern
  2. Saddle area- under tack, increased skin trauma
  3. Face and neck- under tack, increased skin trauma
  4. Distal legs- pastern, coronets, heels
103
Q

what are some clinical signs of dermatophilosis

A

crusts, tufted papules, painful not pruritic, paintbrush lesions (thick creamy, white/yellow/green pus)

104
Q

What is likely cause of these lesions- white, crusty, creamy

A

dermatophilosis

105
Q

how do you dx dermatophilosis

A

hx, clinical signs, cytology (direct smear, saline soaked minced crusts), culture, biopsy

106
Q

what stains can you used to dx dermatophilosis

A

gram stain, diff quick, new methylene blue

107
Q

Dermatophilosis often regress with __weather within 4 weeks

108
Q

what are some topical tx for dermatophilosis

A

iodophors, lime sulfa, chlorhexidine

109
Q

what antibiotics are used to tx dermatophilosis

A

TMS, penicillin/streptomycin

110
Q

what is the most common equine auto-immune skin disease

A

pemphigus foliaceous

111
Q

in pemphigus foliaceous antibodies target __

A

transmembrane protein antigens

112
Q

what is the distribution for pemphigus foliaceous clinical signs

A

face, trunk, coronary bands, edema of legs/ventral abdomen

113
Q

what may be the first sign of pemphigus foliaceous

A

edema of legs/ventral abdomen

114
Q

what are some clinical signs of pemphigus foliaceous

A

exfoliative, scaling, crusting, urticaria, edema

115
Q

what autoimmune disease likely caused this presentation. You also noted lesions at the coronary band and edema of the trunk/legs

A

pemphigus foliaceous

116
Q

how do you dx pemphigus foliaceous

A

hx, clinical signs, cytology, biopsy

117
Q

what do you expect to see on cytology of pemphigus foliaceous

A

acantholytic keratinocytes, non-degenerative neutrophils

118
Q

horse presents with scaling on face and coronary band- cytology showed this- what is arrow pointing at and what is likely cause n

A

Arrow: acantholytic keratinocytes
Dx: pemphigus foliaceous

119
Q

what is tx for pemphigus foliaceous

A
  1. Prednisolone
  2. Dexamethasone
  3. Azathioprine
  4. Aurothioglucose
120
Q

what are some adverse effects of azathioprine

A

bone marrow suppression- increase susceptibility to infection

121
Q

what are some adverse effects of gold salts

A

bone marrow suppression, glomerulonephropathy

122
Q

what is sarcoidosis

A

idiopathic, generalized, systemic granulomatous disease

123
Q

what signs are seen with sarcoidosis

A

exfoliative dermatitis, severe wasting, sarcoidosis granulomatous inflammation

124
Q

in sarcoidosis skin lesions occur first followed by ___

A

internal organ involvement (lungs, GIT)

125
Q

horse presents with severe emaciation and these lesions are present- what is likely cause

A

sarcoidosis

126
Q

how do you dx sarcoidosis

A

hx, clinical signs, biopsy

127
Q

what is the prognosis for skin disease vs GI involvement for sarcoidosis

A

skin dz only- better prognosis
GI involvement: poor prognosis

128
Q

what is tx for sarcoidosis

A
  1. Prednisolone
  2. Omega 6/3 fatty acids
  3. Pentoxifyline
129
Q

is equine pastern dermatitis a disease or syndrome

130
Q

what is a predisposing factor for equine pastern dermatitis in draft horses

A

feathering over fetlocks

131
Q

in equine pastern dermatitis the __aspect of the pastern is more affected

132
Q

what is the mild form of equine pastern dermatitis

A

scratches, mud fever, mud rash

133
Q

what is the exudative form of equine pastern dermatitis

A

grease heel, dew poisoning

134
Q

what is the chronic proliferative form of equine pastern dermatitis

A

grapes, verrucous pododermatitis

135
Q

what signs are associated with equine pastern dermatitis mild form

A

alopecia, dry scale, crusts, epidermal hyperplasia, variable pruritus and pain

136
Q

what signs are seen with exudative form of equine pastern dermatitis

A

erythema, erosion, alopecia, serous to purple T crusts, epidermolysis, vasculitis

137
Q

what is see with chronic proliferative form of equine pastern dermatitis

A

excessive granulation tissue, nodular hyperkeratosis, lichenification, fissures, painful, lameness

138
Q

what form of equine pastern dermatitis is this

A

Chronic proliferative form

139
Q

what for of equine pastern dermatitis is this

140
Q

what form of equine pastern dermatitis is this

A

Exudative form

141
Q

how do you dx equine pastern dermatitis

A
  1. Superficial skin scrape
  2. Cytology
  3. Trichogram
  4. DTM
  5. Biopsy
  6. Culture/deep tissue culture
  7. CBC/chem
142
Q

what is chronic progressive lymphedema and who is most commonly affected

A

defect in dermal and lymphatic elastin fibers

Draft horses

143
Q

what are the early signs of chronic progressive lymphedema

A

swelling and scaling

144
Q

what are the progressive signs of chronic progressive lymphedema

A

lower leg enlargement due to firm swelling, thickened skin fields, large firm nodules

145
Q

draft horse presents with a lot of limb swelling and nodules. What is likely cause

A

chronic progressive lymphedema

146
Q

how do you dx chronic progressive lymphedema

A

hx, clinical signs, cytology, biopsy

147
Q

what is tx for chronic progressive lymphedema

A

no curative tx, palliative care

148
Q

what is photosensitivity

A

increased susceptibility to damaging effects of UVL

149
Q

what is phototoxicity

A

sunburn reaction, dose related response to light exposure

150
Q

UV_ less than __nm is not damaging to cells

A

UVC, less than 290nm

151
Q

UB_, ___-___nm results in sunburn or erythema spectrum

A

UVB, 290-320

152
Q

UV__, __-___nm penetrates deeper and associated with photosensitivities

A

UVA, 320-400nm

153
Q

what are the 3 basic features of photosensitivity

A
  1. Photodynamic agent
  2. Exposure to sufficient amounts of UVL
  3. Cutaneous absoprtion- lack of pigment in hair and skin
154
Q

what are some examples photodynamic agents

A

Plants: St. John’s worts, buck wheat

Mycotoxins

Drugs/chemicals: phenothiazines

155
Q

what is primary photosensitivity

A

photodynamic agent ingested

156
Q

what is hepatogenous photosensitivity

A

hepatotoxic plant

157
Q

you go to farm to evaluate these lesions and notice a lot of St. John wort plants. What likely caused these lesions

A

Photosensitivity reaction

158
Q

how do you dx photosensitivity

A

Hx, look for plants, lesions, CBC/chem-liver abnormalities

159
Q

what is tx for photosensitivity

A
  1. Eliminate photodynamic agents
  2. Avoidance of sunlight
  3. Tx hepatic disease
  4. Tx secondary infection
  5. Glucocorticoids
  6. NSAIDS

Equine Med and Surgery II (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions