Difference between revisions of "Psoroptic Mange"

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Caused by [[Psoroptes]]
+
Caused by [[Psoroptes]]  
  
*Occurs in cattle, sheep, horses, goats, rabbits and other animals
+
*Occurs in cattle, sheep, horses, goats, rabbits and other animals  
*Host-specific
+
*Host-specific  
 
*[[Psoroptes cuniculi|''Psoroptes cuniculi'']] in ear canals of rabbits, horses, goats and sheep
 
*[[Psoroptes cuniculi|''Psoroptes cuniculi'']] in ear canals of rabbits, horses, goats and sheep
'''Pathogenesis'''
+
 
 +
'''Pathogenesis'''  
 +
 
 
*The ears are painful and intensely pruritic
 
*The ears are painful and intensely pruritic
  
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*Mites are grossly visible
 
*Mites are grossly visible
  
*Histologically, there is chronic erosive and proliferative eosinophilic dermatitis
+
*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
 
**The mites are non-burrowing and thus are found only in the exudate, not in the tissue
  
 +
<br>'''Diagnosis'''
  
'''Diagnosis'''
 
 
*Microscopic examination for mites (low magnification)
 
*Microscopic examination for mites (low magnification)
  
 
*Appearance
 
*Appearance
  
 +
<br>'''Control'''
  
'''Control'''
+
*Infestations are difficult to eliminate from a colony  
*Infestations are difficult to eliminate from a colony
 
 
**Ivermectin is usually effective.
 
**Ivermectin is usually effective.
  
 +
<br>
  
*[[Psoroptes|''P.equi'']] at base of mane, tail and forelock in horses
+
*[[Psoroptes|''P.equi'']] at base of mane, tail and forelock in horses  
*[[Psoroptes ovis|''P.ovis'']] in sheep ('''sheep scab''')and cattle
+
*[[Psoroptes ovis|''P.ovis'']] in sheep ('''sheep scab''')and cattle  
**Thickened skin and dry scales and crusts
+
**Thickened skin and dry scales and crusts  
**Starts at withers and spreads due to self trauma
+
**Starts at withers and spreads due to self trauma  
**Microscopically:
+
**Microscopically:  
***Spongiotic, hyperplastic or exudative superficial perivascular dermatitis
+
***Spongiotic, hyperplastic or exudative superficial perivascular dermatitis  
***Eosinophils[[Category:To_Do_-_Clinical]]
+
***Eosinophils
  
 +
<br>
  
 +
=== Pathogenesis ===
  
===Pathogenesis===
 
 
*Economically important ectoparasite of sheep
 
*Economically important ectoparasite of sheep
  
*Causes '''sheep scab'''
+
*Causes '''sheep scab'''  
**Wool loss, restlessness, biting, scratching of infested area and decreased productivity through decreased weight gain
+
**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)
+
**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
+
**Population numbers decline after shearing due to a change in the micro-climate, then build up again as the fleece grows  
 
**'''Notifiable in UK'''
 
**'''Notifiable in UK'''
  
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*Antigenic material in mite faeces can lead to hypersensitivity reactions
 
*Antigenic material in mite faeces can lead to hypersensitivity reactions
  
===Diagnosis===
+
=== Diagnosis ===
 +
 
 
*Skin scraping
 
*Skin scraping
  
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*Examine under a microscope
 
*Examine under a microscope
  
 +
<br>
 +
 +
=== Treatment ===
  
===Treatment===
+
*Sheep  
*Sheep
+
**Plunge dipping; no less than 1 minute and must dip head at lease once  
**Plunge dipping; no less than 1 minute and must dip head at lease once
 
 
**Can treat with avermectins or milbemycins by injection
 
**Can treat with avermectins or milbemycins by injection
  
*Cattle, horses and rabbits
+
*Cattle, horses and rabbits  
**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
  
 
+
To_Do_-_Kate [[Category:Integumentary_System_-_Mite_Infections]]
 
 
[[Category:Integumentary System - Mite Infections]]
 
[[Category:To_Do_-_Clinical]]
 

Revision as of 11:38, 1 March 2011

Caused by Psoroptes

  • Occurs in cattle, sheep, horses, goats, rabbits and other animals
  • Host-specific
  • Psoroptes cuniculi in ear canals of rabbits, horses, goats and sheep

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.


  • P.equi at base of mane, tail and forelock in horses
  • P.ovis in sheep (sheep scab)and cattle
    • Thickened skin and dry scales and crusts
    • Starts at withers and spreads due to self trauma
    • Microscopically:
      • Spongiotic, hyperplastic or exudative superficial perivascular dermatitis
      • Eosinophils


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

To_Do_-_Kate