Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CAEM Pt. 2 > Exam #3: Equine Derm > Flashcards

Exam #3: Equine Derm Flashcards

1
Q

Six main categories of equine derm problems

A

1) Pruritus
2) Crusting and scaling
3) Ulcers and erosions
4) Lumps and bumps
5) Discoloration
6) Hair coat changes

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

Main diagnostics tests for equine derm conditions (8)

A
  • Similar to small animal derm
    1) Skin scrape
    2) Combings of mane, tail, feathers (ectoparasites)
    3) Scotch tape preps (cytology)
    4) Trichograms
    5) Dermatophyte culture- monitor freq so it’s not overgrown by normal bacteria of saprophytic fungi
    6) Impression smear or crust cytology
    7) Culture for bacterial or fungus
    8) Skin biopsy
  • Suspect systemic dz? run CBC, chem, diet elimination trials, intradermal testing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Top four differentials for pruritus in horses

A

1) Ectoparasites
2) Insect hypersensitivity
3) Allergic hypersensitivity
4) Urticaria

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

DDx? Pruritus of lower legs, tail, foot, (may become generalized), “scratches”, alopecia, crust formation

A

> Mites

  • Most commonly in horses is Chorioptes (legs, tail, foot)
  • Psoroptes (droopy ears, mane, trunk involvement)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Treatment of choice for mites

A

Ivermectin, others = 5% lime sulfur

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

Dx? Intense pruritus, beginning on the head, non-follicular papules, crusts, excoriations, alopecia

A

Mites = Sarcoptes

  • Cross-species transmission possible
  • Reportable and zoonotic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What time of year are parasitic skin pathologies more common?

A

Winter = often more severe then

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

Dx? Pruritus, restlessness, poor hair coat quality, alopecia, excessive grooming of mane, head, tail, fetlocks (affected animals may be asymptomatic and just “twitchy”)

A

> Lice (pediculosis)

  • Common in young or old/debilitated animals
  • Overcrowding predisposes
  • Common in colder months
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Common anatomic locations of biting and sucking lice

A
  • Biting louse (Damalina) = dorsolateral trunk, mobile

- Sucking louse (Haematopinus) = mane, tail, fetlock, stationary

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

Difference in location on horse between Chorioptes and Psoroptes

A

1) Chorioptes = leg, tail, foot

2) Psoroptes = ears, mane, tail

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

Treatment of lice

A
  • Treat all animals in contact = ivermectin

- Clean environment

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

Dx? Pruritus, papules, wheals on muzzle and distal limbs

A

Chiggers (common in late summer/fall)

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

Dx? Anal pruritus, tail rubbing and alopecia

A

Pinworms - Oxyuris equi

DDX: tail pyoderma, insect bite hypersensitivity, atopic dermatitis, food allergy, chorioptic/psoroptic mange

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

True or false - pinworms are species specific?

A

True

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

Dx? Pruritus, painful papules and wheals with a central crust

A

> Biting flies

  • Tabanids = horse flies = ventrum, legs, neck, withers (individual strikes/bites)
  • Stomoxys = stable flies = neck, back, groin, chest, legs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Dx? Ventral midline dermatitis

A

Horn fly bites

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

What is the most common allergic skin disease in horses?

A

Insect bite hypersensitivity

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

Dx? Pruritus (location varies, common face, mane, tail, ventrum, dorsum), papules, wheals, crusts, secondary alopecia, self trauma (etc.)

A

Hypersensitivity to Culicoides fly saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Treatment of insect bite hypersensitivity

A

1) Limit insect exposure
2) Environmental control
3) Anti-histamines
4) Topical and systemic steroids
+/- Immunotherapy (conflicting evidence)

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

Dx? Chronic urticaria, generalized pruritus, secondary excoriations, lichenification, alopecia

A

Atopic dermatitis to environmental antigens

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

Diagnosis and treatment of atopic dermatitis

A
  • Dx: exclusion

- Tx: symptomatic (corticosteroids, anti-histamines), immunotherapy

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

Which is more common with pruritus in horses: food allergy or contact reactions?

A
  • More common = contact reactions, Ex: tack, saddle, irritants.
  • Rare = food allergy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How do we view urticaria in horses?

A

> REACTION PATTERNS from different etiologies or pathogeneses (angioedema)
+ Wheal (flat topped with steep walled sides)
*Should “pit” with pressure

24
Q

DDx for urticaria (6)

A

1) Hypersensitivity reactions
2) Drug rxns
3) Physical = cold temp, exercise induced, dermatographism
4) Stress
5) Vasculitis
6) Arthropods

25
Q

Three MAIN differentials for crusting and scaling?

A

1) Dermatophytes
2) Dermatophilosis
3) Bacterial folliculitis due to Staph

26
Q

Dx? Papules, crusts, areas of alopecia (with or w/o crusts), scaling, common to start in axillary and girth region, variable prutitus

A

Dermatophytes - commonly Trichophyton

DDx: dermatophilosis, bacterial pyoderma, demodicosis, pemphigus folliaceus

27
Q

Dx and tx of ringworm

A
  • Dx: DTM culture, trichogram, skin biopsy

- Tx: environmental and tack decontamination, topical lime sulfur, chlorhex/azole antifungal shampoo

28
Q

Dx? “Paintbrush lesions” with yellow exudate, ulcerated skin, pain, railroad track cocci on cytology

A

Dermatophilosis (Dermatophilus congolensis)

Predisposing factors = moisture, skin damage, chronic carrier animals

29
Q

Tx of dermatophilosis

A
  • Dry the horse
  • Remove crusts (remove from environment)
  • Topical antibiotics (systemic in severe cases)
30
Q

Dx? Crusts, epidermal collarettes, papules, +/- pruritus, alopecia - common near the saddle, pastern (“scratches”) and tail

A

Bacterial folliculitis (pyoderma) from coag + Staph

DDx: Dermatophilosis, dermatophytosis, insect bite hypersensitivity, atopic dermatitis, ectoparasites

31
Q

Dx and tx of bacterial folliculitis (pyoderma)

A
  • Dx: cytology by tape prep or glass side impression

- Tx: systemic antibiotics, possibly topical with localized lesions

32
Q

Dx? Scaling dermatitis with variable pruritus (common intermammary)

A

Malassezia yeast

Tx: topical antifungal shampoos

33
Q

Causes of dermatologic ulcers and erosions

A

Progression of other “lesser” signs = pruritus, crusting/scaling

Ex: secondary to self-induced excoriations from pruritus (Ex: hypersensitivity), from underneath crusts

34
Q

Cause of perineal ulceration

A

Fecal or urine scaling from poor management

Tx: wash with warm/chlorhex water, cover with antibacterial ointment

35
Q

DDx for mucocutaneous ulcerations (5)

A

1) Trauma
2) Drug reactions
3) Infectious = vesicular stomatitis
4) Immune-mediated - bullous pemphigus
5) Congenital - epidermolysis bullosa

36
Q

What is HERDA?

A

Hereditary equine regional dermal asthenia - hyperextensible fragile skin due to collagen abnormality, lesions in areas of friction or trauma

37
Q

DDx for lumps and bumps (6)

A

1) Sarcoids
2) Papillomatosis
3) Eosinophilic granulomas
4) Abscesses
5) Habronemiasis
6) Skin tumors (melanoma, SCC)

38
Q

Dx and cause: wart in an adult animal

A

Sarcoid until proven otherwise (due to bovine papillomavirus type I and II)

  • Most common equine skin tumor
  • Types: occult, nodular, malevolent, verrucous, fibroblastic, mixed
39
Q

Dx and tx of equine sarcoids

A
  • Dx: biopsy (may stimulate growth afterwards)

- Tx: immunomodulating meds, cryotherapy. surgical excision, imoquimod

40
Q

Dx and cause: wart-like cauliflower lesions on muzzle and distal limbs of young animals, often aural

A

Equine papillomatosis

41
Q

Dx and tx of equine papillomatosis

A
  • Dx: biopsy

- Tx: most spontaneously regress, speed it up with surgical excision or cryotherapy (aural masses rarely regress)

42
Q

Most common non-neoplastic nodular skin disease

A

Eosinophilic granuloma

43
Q

Dx? Single or multiple, well-circumscribed, haired, non-traumatized dermal nodules, non-painful, non-pruritic

A

Eosinophilic granuloma - may be associated with underlying hypersensitivity disorders

44
Q

Common etiologic agent with pectoral region abscesses

A

Corynebacterium pseudotuberculosis = pigeon fever

45
Q

Etiologic agents with abscesses (3)

A

1) Corynebacterium pseudotuberculosis (via fly vectors)
2) Sporothrix schenkii
3) Pythium insidiosum (swamp cancer)

46
Q

Dx? Lesions/nodules on legs, ventral prepuce, urethral penile process, medial ocular canthus, chronic granulomatous inflammation, ulceration, exuberant granulation tissue

A

Habronemiasis - hypersensitivity to Habronema larvae in wounds or skin

DDx: infectious granulomas, eosinophilic granuloma, neoplasia, exuberant granulation tissue

47
Q

Dx and tx of habronemiasis

A
  • Dx: biopsy

- Tx: local and systemic ivermectin, debulk large lesions, systemic glucocorticoids

48
Q

Dx? Tx? mass on eyelid or external genitalia, commonly in light colored horses

A

Squamous cell carcinoma

Tx: wide surgical excision, some chemo options

49
Q

Dx? Tx? masses on the undersurface of the tail and perianal region, common in grey horses

A

Melanoma

Tx: wide surgical excision, radio/chemotherapy

50
Q

DDx for coat discoloration (5)

A

1) Photosensitization
2) Leukotrichia, leukoderma
3) Hyperpigmentation
4) Effluvia, defluxion
5) Retained hair coat

51
Q

Dx? Most common cause of hairless, white, or lightly pigmented areas of skin

A

Photosensitization

52
Q

Two main types of photosensitization in the horse

A

1) Primary - ingestion of metabolically derived photodynamic agents that reach the skin
2) Hepatogenous = liver function can’t detoxify

53
Q

Dx and tx of photosensitization

A
  • Dx: history, PE, liver function test

- Tx: eliminate offending agent, limit sun exposure, symptomatic tx of hepatic disease, +/- antibiotics

54
Q

Causes of leukotrichia or leukoderma

A

> Depigmentation of hair

  • Breed-related = thoroughbreds, Arabians
  • Drug/vax associated
  • From painful crusts
  • LEUKODERMA = from trauma/damage to the skin
55
Q

Cause of vitiligo

A

Inherited condition, common in Arabs

56
Q

Four main differentials for alopecia

A

1) Pruritus
2) Systemic illness = anagen/telogen defluxion
3) Light exposure
4) Nutritional status

57
Q

Cause of retained hair coats (2)

A
  • Poor health and management

- Underlying systemic disease (PPID)

CAEM Pt. 2 (27 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions