Equine dermatology pt 3

Question 1

immune-mediated vasculitis
- what type of reaction
- etiology
- clinical signs

Answer 1

§ Type I, II, or III hypersensitivity reactions
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Etiology
§ Equine viral arteritis
§ Equine influenza
§ C. pseudotuberculosis
§ Streptococcus spp.
§ Idiopathic
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Clinical signs
§ Edema, erythema
§ Petechiae, ecchymoses
§ Oral ulcers and bullae

Question 2

immune-mediated vasculitis
- Dx
- Tx

Answer 2

Diagnosis
§ Dependent on etiology
> SeM protein antibody titers
> Skin biopsies
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Treatment
§ Underlying cause
§ Immunosuppression
> Corticosteroids
§ Supportive case
> Hydrotherapy
> Limb bandages

Question 3

distribution of sarcoids in horses

Answer 3

-51% head and ears
- 25% limbs and shoulders
- 24% neck, trunk, and genetalia

Question 4

sarcoids
- implicated agents
- risk factors
- signalment
- Dx

Answer 4

Viral induced
§Bovine papilloma virus 1 and 2
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Risk factors
§ Cattle
§ Superficial wound
§ Familial predisposition
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Signalment
§ >1 year of age
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Diagnosis
§ Appearance
§ Biopsy

Question 5

sarcoids Tx

Answer 5

§Benign neglect
§ Wide surgical excision
§ Radiation
§ Cryotherapy
§CO2 laser
§BCG immunostimulation
§Intralesional cisplatin or 5-FU
§ Imiquimod
§Blood root extracts (Xxterra)

Question 6

squamous cell carcinoma
- how common?
- etiology
- location

Answer 6

Second most common skin neoplasia
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Etiology
§ UV radiation exposure
§ Papillomavirus infection
§ Carcinogenic properties of smegma
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Location
§ Unpigmented skin
§ Mucocutaneous junctions
§ Periocular and penile most common

Question 7

squamous cell carcinoma
- invasiveness, metastasis
- Dx
- Tx

Answer 7

Locally invasive
§Low metastatic rate
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Diagnosis
§ Biopsy
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Treatment
§ Wide surgical excision
§ Cryosurgery
§ Radiation therapy
§ Topical 5-fluorouracil
§ Intralesional cisplatin
§ Piroxicam

Question 8

melaonoma
- what is it
- risk factors
- anatomic location

Answer 8

§Malignant transformation of melanocytes
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Risk factors
§ Grey coat color
> Increased incidence with increasing age
> 67-80% > 15 years
§ Arabians, Thoroughbreds, Percherons
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Location
§ Perineum, tail, external genitalia
§ Face
§ Parotid salivary gland, guttural pouch

Question 9

melanoma
- progression, metastasis
- Dx
- Tx

Answer 9

Progressive with age
§ Locally aggressive
§ High metastatic rate
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Diagnosis
§ Appearance
§ Biopsy
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Treatment
§ Monitoring
§ Surgical excision
§ Cisplatin
§ Cimetidine
§ Canine melanoma vaccine (Oncept)

Question 10

eosinophilic granuloma
- how common, appearance
- locations
- Dx
- Tx

Answer 10

Very common
§ Single or multiple
§ 0.5-10cm diameter
§ Firm, round, and raised
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Locations
§ Withers, back, neck
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Diagnosis
§ Physical exam +/- biopsy
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Treatment
§ Surgical removal
§ Intralesional corticosteroid

Question 11

hereditary equine regional dermal asthenia
- what is this
- inheritance
- breeds
- progression, signs
- Tx

Answer 11

§ Autosomal, recessive mutation
§ Quarter horses, Paints, Appaloosas
§AQHA requires DNA testing
§Normal at birth
§By 2 years of age:
>Hyperextensible skin
> Disfiguring scars
§Not treatable

Question 12

warmblood fragile foal syndrome
- inheritance
- signs
- Tx

Answer 12

§ Autosomal, recessive mutation
§ Abortions or stillbirths
§ Abnormal at birth:
> Thin, friable skin
> Severe joint laxity >May prevent standing
> Incomplete abdominal wall
§No treatment

Question 13

junctional epidermolysis bullosa type 1 and 2
- what breeds affected by types
- inheritance
- clinical signs
- Tx

Answer 13

§ Type 1- French and Belgian Draft horses
§ Type 2- American Saddlebreds
§ Autosomal recessive mutation
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Clinical signs
§ Blisters, erosions, ulcerations
> Skin and mucous membranes
§ Dental abnormalities
> Early eruption
> Enamel pitting
§ Hoof sloughing
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§ No treatment

Question 14

primary photosensitization
- etiology
- clinical signs
- Tx

Answer 14

Etiology
§Photodynamic agent:
§ Ingestion- St. John’s wort
§ Contact- Clovers, fly spray
§ Injection- Tetracyclines
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Clinical signs
§ Erythema, edema, erosions
§Amelanotic/ poorly haired areas
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Treatment
§ Decrease UV exposure
§ Remove from source

Question 15

thermal / chemical injury
- classification of burns
- at what extent is there increased mortality
- time it takes for full extent
- other considerations

Answer 15

§1st degree
> Erythema, edema, desquamation

§2nd degree
> Vesicles, necrosis, eschar formation

§3rd degree
> Loss of cutaneous sensation, eschar formation
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§Burns covering >50% of skin > increased mortality
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§ Up to 14 days for full extent of injury
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Other considerations
§ Corneal ulcers/ edema
§ Smoke inhalation

Question 16

thermal / chemical injury
- triage
- secondary assessment, Tx

Answer 16

Triage
§ Relocate to safe area
§ Apply cold water to affected areas
§ Provide analgesics
§ Provide intravenous fluid therapy
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Secondary assessment
§ Leave eschar intact
§ Clean areas without eschar
> Mild soap is best
§ Apply occlusive dressing
> Honey
> Silver sulfadiazine
§ Bandage lightly
§ Repeat

Question 17

skin scalding
- risk factors
- Tx

Answer 17

Risk factors
§Foals
§ Diarrhea
§Neurologic disease/dysfunction
§Urinary tract disease
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§ Address underlying condition
§ Clean affected area frequently
> Apply zinc oxide to affected areas
> Apply petroleum jelly to unaffected areas

Question 18

pressure necrosis
- risk factors
- Tx

Answer 18

Risk factors
§ Prolonged/increased recumbency
§ Poorly fitting tack
§ Over-tight or poorly applied bandages
§ Casts/ splints
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Treatment
§ Remove instigating factor
§ Improve bedding material/ depth
§ Rotate animal frequently
§ Daily cleaning and debridement
§ Topical antimicrobial
§ Protect affected areas