Sarcoptic Mange

Transmission

Puppy with sarcoptic mange
Caroldermoid 2006, Wikimedia Commons

• Close contact

• Adults and larvae can be transferred from one skin surface to another

Pathogenesis

• Erythema with papule formation

• Scale and crust formation
  • Alopecia

• Intense pruritus for 1 week
  • Self-inflicted trauma
  • Scab formation

• Wrinkling and thickening of skin

• Hypersensitivity may develop
  • Rash develops

Sarcoptes scabiei

• Causes scabies

• Strains of S. scabiei can be passed between different animals and cause clinical signs although the infection is likely to resolve spontaneously and be unlikely to establish

Diagnosis

• Skin scraping until capillary blood appears
  • Adults, eggs, immature mites and faecal pellets can be seen microscopically

• Place material on a microscope slide

• Add 10% KOH

• Warm slide over bunsen flame

Treatment

• Acaricide
  • For more information on acaricides click here

• Treat both infected and in-contact animals

• Older products have to be given in repeat treatments

• Avermectins are effective in farm animals

• Selamectin is available as a good spot-on for dogs

Dog

• Sarcoptic Mange is highly contagious
• Intense pruritus
• First signs appear at edges of ears, then progresses to muzzle, face and elbows

Cat

• Is rare

Horse

• Caused by Sarcoptes scabiei
• Highly contagious
• Mainly in pigs, dogs, also horses, cattle, sheep, goats and cats
• Intense pruritus due hypersensitivity to mites borrowing through stratum corneum
• Usually starts with external pinnae -> head -> neck -> generalised
• Grossly:
  • Erythematous macules, papules, crusts
  • If chronic -> lichenified, hairless
• Microscopically:
  • Hyperplastic, spongiotic, superficial perivascular dermatitis
  • Crusting, eosinophil infiltration
  • Mites are not commonly seen, but eggs and feces may be found in stratumn corneum

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