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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| − | + | *Causes [[Parasitic skin infections - Pathology#Psoroptic mites|psoroptic skin infestation]] | |
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| − | + | '''Recognition''' | |
| + | *Oval shaped | ||
| − | + | *Long legs | |
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| − | + | *Funnel shaped suckers on '''segmented''' pedicels | |
| − | '' | ||
| − | + | *1-2mm in length | |
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| + | '''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''==== | ||
| + | |||
| + | *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 | ||
| + | |||
| + | |||
| + | ====''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 | ||
Revision as of 22:31, 5 April 2010
- Causes psoroptic skin infestation
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
- 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
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