Difference between revisions of "Psoroptes"

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(Created page with '*Causes psoroptic skin infestation '''Recognition''' *Oval shaped *Long legs *Funnel shaped suckers on '''segmented'…')
 
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====''Psoroptes cuniculi''====
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[[Psoroptes cuniculi|''Psoroptes cuniculi'']]
  
*Parasite of rabbits
 
 
*Common among conventional rabbits
 
 
*Transmitted via contact
 
 
*Adapted to living in an aural environment
 
 
 
'''Pathogenesis'''
 
*The ears are painful and intensely pruritic
 
 
*Affected rabbits shake their heads and scratch their ears
 
 
*The inner surfaces of the pinnae are covered with brown, scaly, fetid material, and the skin beneath is raw
 
 
*Mites are grossly visible
 
 
*Histologically, there is chronic erosive and proliferative eosinophilic dermatitis
 
**The mites are non-burrowing and thus are found only in the exudate, not in the tissue
 
 
 
'''Diagnosis'''
 
*Microscopic examination for mites (low magnification)
 
 
*Appearance
 
 
 
'''Control'''
 
*Infestations are difficult to eliminate from a colony
 
**Ivermectin is usually effective
 
  
  
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**No licensed product for horses in the UK
 
**No licensed product for horses in the UK
 
**Cattle and rabbits can be treated with avermectins, milbemycins or topical acaricides
 
**Cattle and rabbits can be treated with avermectins, milbemycins or topical acaricides
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[[Category:Non-Burrowing Mites]]

Revision as of 22:34, 5 April 2010


Recognition

  • Oval shaped
  • Long legs
  • Funnel shaped suckers on segmented pedicels
  • 1-2mm in length


Life cycle

  • Confined to skin surface
  • Feed on serous exudate by siphoning
  • Adult female can lay up to 100 eggs during her life time (1 month)
  • 10 day life cycle
  • 2 nymphal stages


Psoroptes cuniculi


Psoroptes ovis

  • Adult females are large mites at 750μm in length
  • Males identified by copulatory suckers and paired posterior lobes
  • Males attach to deutonymphs (second moult after larval stage) in a process called copula
    • Males remain in copula until females moult for the last time
    • Copulation occurs
  • Life cycle last 14 days
  • Transmitted by direct contact between sheep
  • Indirect transmission can also occur


Pathogenesis

  • Economically important ectoparasite of sheep
  • Causes sheep scab
    • Wool loss, restlessness, biting, scratching of infested area and decreased productivity through decreased weight gain
    • Usually seen in late autumn and early winter (although may also occur in late summer)
    • Population numbers decline after shearing due to a change in the micro-climate, then build up again as the fleece grows
    • Notifiable in UK
  • Mites found under scabs and in skin folds
  • Lesions most common on flanks, neck, back and shoulders
  • Causes pruritic condition of cattle
  • Active in keratin layer
  • Mouthparts abrade the skin
  • Antigenic material in mite faeces can lead to hypersensitivity reactions


Diagnosis

  • Skin scraping
  • KOH added
  • Warm slide over a bunsen flame
  • Examine under a microscope


Treatment

  • Sheep
    • Plunge dipping; no less than 1 minute and must dip head at lease once
    • Can treat with avermectins or milbemycins by injection
  • Cattle, horses and rabbits
    • No licensed product for horses in the UK
    • Cattle and rabbits can be treated with avermectins, milbemycins or topical acaricides