Difference between revisions of "Psoroptic Mange"
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| Line 4: | Line 4: | ||
*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''' | ||
| + | *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|''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 | ||
Revision as of 11:43, 9 July 2010
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