Small Ruminant/Camelid Dermatology

Question 1

What is Pediculosis

Answer 1

• Lice:
  
  • Biting - Damalinia ovis, caprae
  • Sucking - Linognathus ovillus, stenopis

Question 2

What are the different types of mange of small ruminants/camelids

Answer 2

Question 3

What is Chorioptic mange

Answer 3

• Distribution: leg & tail
  
  • lower hind limbs
  • scrotum (sheep)
• Appearance;
  
  • papules
  • erythema
  • scale
  • crust
  • ulcers
  • alopecia
• Less common in goats
• Associated with poor immune system/nutrition
• Varying pruritis

Question 4

Wat is Psoroptic mange

Answer 4

• Debilitating pruritis
• Distribution:
  
  • ears - Goats
  • Wooled areas
• Appearance:
  
  • papules
  • crusts
• Sequelae: otitis externa

Question 5

WHat is Sarcoptic mange

Answer 5

• Debilitating pruritis
• Distribution:
  
  • head & neck
  • generalized; non-wooled areas (sheep)
• Appearance:
  
  • papule
  • scaling
  • crusting
  • ulceration
  • alopecia

Question 6

What is Demodectic mange

Answer 6

• Distribution:
  
  • face
  • periocular (sheep)
  • Shoulder
  • neck
• Appearance:
  
  • nodular (sheep_
  • caseous (goats_
  • Purulent ribbons
• Sequelae: secondary pyoderma
• DIfferentials for goats: Caseous lymphadenitis

Question 7

What is Sheep Keds?

Answer 7

• Melophagus ovinus
  
  • 6 legs, no wings
• Life cycle: 6 weeks on host
• Suck blood
• Distribution:
  
  • NOT dorsal
  • brisket
  • shouler
  • flank
  • rump
• Apearance:
  
  • pruritic (wool break, stained wool)
• Sequelae:
  
  • ill thrift
  • decreased hide quality
  • anemia

Question 8

How are ectoparasites diagnosed?

Answer 8

Question 9

What is Zinc Responsive Dermatosis

Answer 9

• Risk factors:
  
  • Alfalfa (Ca++), over-liming soil with salts
  • hereditary components - Autosomal recessive defect in A46
  • Dairy sheep
• Distribution:
  
  • bilateral symmetric: face/muzzle and ears, back, legs, coronary band, udder
• Appearance:
  
  • inflammation/crusts
  • generalized parakeratosis, hair loss/greying
  • pruritus
• Sequelae/ associated conditions:
  
  • Diarrhea
  • weight loss
  • abnormal claw growth
  • stunted growth
  • kyphosis
  • anorexia
• Dx:
  
  • Biopsy
  • skin scrap (rule out ectos)
  • serum zinc
• Tx:
  
  • Zn supplementation

Question 10

Differentials for masses and bumps

Answer 10

• Contagious ecthyma
• ulcerative dermatosis
• dermatophilosis
• sheep/goat pox
• pemphigus foliaceous

Question 11

Contagious Ecthyma

Answer 11

• “orf”
• Cause: Epitheliotropic DNA parapoxvirus
  
  • encodes for VEGf-like protein
    
    • vascular permeability, angiogenesis, endothelial cell proliferation
• Risk:
  
  • young
  • immunologically naive
  • Boer goats predisposed
• Epidemiology:
  
  • dried scabs - virus persists for years
  • subclinical carriers
  • 2-14day incubation
  • 2-3 week disease course
• Distribution:
  
  • mucocutaneous junctions:
    
    • lips, nostrils, oral mucosa eyes face
  • Older: udder, coronary band interdigital, genitalia
• Appearance:
  
  • papular/vesicular/pustular
  • proliferative dermatitis - raised proliferative, coalescing, thick and durable scab
• Sequelae:
  
  • no scar
  • secondry fusobacerium necrophorum infection
  • pneumonia
  • arthritis
  • lymphadenopathy
  • GI disease
• Dx:
  
  • gross appearance
  • biopsy + PCR/IHC/electron microscopy
• Tx:
  
  • self limiting
  • do NOT remove crusts
  • Topical disinfectants, antibiotics, insecticides
  • Euthanaisa in atypical cases
• Immunity: decreases duration and sevarity
  
  • colostral - limited
  • Vaccine - Live; only if confirmed existence/persistence
• DDx: Pox, Bluetongue, Ulcerative dermatosis

Question 12

What is atypical malignant orf?

Answer 12

• Persistent - does not spontaneously regress
• Malignant
• Unusuall distribution
  
  • lower limbs
  • head

Question 13

papillomas

Answer 13

• Rare:
  
  • mammary, cutaneous, non-mammry genital
• Goats: teats
  
  • can progress to SCC
  • Saanen highest risk
• Sheep: face/legs
  
  • most common cancer of the ear
• Dx: Biopsy

Question 14

Sheep/goat pox

Answer 14

• Capripoxviruses
• Sheep have greater severity - mortality up to 80%
• Lesions similar to Orf
• Systemic disease:
  
  • fever
  • conjunctivitis
  • anorexia
  • rhinitis
• Mixed infections with other virus/bacteria possible
• attenuated vaccines vailable

Question 15

Dermatophilosis

Answer 15

• Distribution:
  
  • dorsum
  • distal extremities
  • muzzle
  • Kids - ear pinnae, under tail
• Appearance:
  
  • paintbrush
  • coalescing scab
  • keratinized wart
• Other syndromes
  
  • strawberry foot rot
  • lumpy wool

Question 16

Differentials for scaling & alopecic skin

Answer 16

• Ectoparasites - Pediculosis & mange
• Zinc responsive dermatosis
• Pemphigus foliaceus
• Dermatophytosis
• Photosensitization
• wool break

Question 17

Pemphigus foliaceous

Answer 17

• Generalize exfoliative dermatitis
• Pathogenesis: immune-mediated acantholysis
  
  • auto-antibodies against transmembrane proteins
    
    • bind, release proteloytic enzymes ⇢ destruction of intracellular attachments of epidermal cells
  • Rounding of epidermal cells leads to clefts and vesicles
• Distribution:
  
  • ventrum
  • limbs
  • perineal
• Appearance;
  
  • pustule
  • Scale
  • crust
  • epidermal
  • collarettes
  • erosions
  • +/- prurutis/pain
• Consider in animals with exfoliative disease, refractory to traditional treatment
• Dx:
  
  • Biopsy
    
    • intradermal acantholysis - intragranular/sub corneal clefts & vesicles
    • Intracellular deposition of immunoglobulin
    • +/- neutrophils and eosinophils
• Tx: Corticosteroids
  
  • prednisolone
  • dexamethasone

Question 18

Club lamb fungus

Answer 18

• Trichophyton verucossum, T. gypseum, T. mentagophytes, Microsporum canis
• Risk factors:
  
  • young, naive
  • loss of lanolin from excessive rinsing
  • show animals
• up to 16 week disease course

Question 19

Wool Break/Telogen Effluvium

Answer 19

• Wool easily epilates with no underlying lesion or discoloration
• Risk factors:
  
  • diet, trace mineral deficiency (Cu?)
  • stress
• Dx:
  
  • rule out other diseases - ectoparasites
• Tx:
  
  • none
  • supportive care
    
    • warmth
    • protect from sunburn