Pathogenesis and epidemiology

  • Squamous demodecosis
    • Less serious
    • Dry reaction
    • Alopecia, desquamation and skin thickening
    • Absent to mild pruritus
  • Follicular/pustular demodecosis
    • More serious
    • Skin invasion by staphylococci
    • Skin becomes wrinkled, thickened and contains pustules which ooze serum, blood or pus
    • Affected animals may be seriously disfigured
    • Severe pruritus is associated with secondary infection
  • Immune factors are important in determining the severity and occurrence of demodecosis
    • Familial susceptibility
    • Immunosuppression
    • Immunosuppressant therapy

Diagnosis

  • Liquid paraffin applied to a skin fold
  • Deep skin scraping

Control

  • Not easily accessible to acaricides due to their deep location in the skin
  • Repeat treatments needed
  • Recovery may take several months
  • To aid acaricide penetration, clipping a dog's coat and washing is recommended


Dogs

Cats


Cattle

  • Pea-sized nodules in the skin
    • Each nodule contains several thousand mites
  • Affects hide quality
    • Economically important in Australia


Goats

  • Becoming more common in goats
  • Disease similar to that in cattle


Pigs, Sheep and Horses

  • Rare