Difference between revisions of "Psoroptes ovis"
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(Created page with '*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 st…') |
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− | + | *Adult females are large mites at 750μm in length | |
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− | + | *Males identified by copulatory suckers and paired posterior lobes | |
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− | + | *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 | |
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− | + | *Indirect transmission can also occur | |
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− | + | '''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 | |
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+ | *Active in keratin layer | ||
− | + | *Mouthparts abrade the skin | |
− | + | *Antigenic material in mite faeces can lead to hypersensitivity reactions | |
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− | [[Category: | + | '''Diagnosis''' |
+ | *Skin scraping | ||
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+ | *KOH added | ||
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+ | *Warm slide over a bunsen flame | ||
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+ | *Examine under a microscope | ||
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+ | '''Treatment''' | ||
+ | *Sheep | ||
+ | **Plunge dipping; no less than 1 minute and must dip head at lease once | ||
+ | **Can treat with avermectins or milbemycins by injection | ||
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+ | *Cattle, horses and rabbits | ||
+ | **No licensed product for horses in the UK | ||
+ | **Cattle and rabbits can be treated with avermectins, milbemycins or topical acaricides[[Category:Sheep]][[Category:Cattle]] |
Revision as of 22:37, 5 April 2010
- 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