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== Synonyms ==
== Synonyms ==
*Sheep Scab
*Sheep Scab
*Psoroptic scabies
*Psoroptic scabies
*Psoroptosis
*Psoroptosis
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== Introduction ==
Psoropitc mange is the disease caused by the '''non-burrowing''' mite, ''Psoroptes ovis ''(common name Scab mite), which affects sheep.
Other species of Psoroptes mite affect a variety of species including Cattle, Goats, Horse, Rabbit, Camelid, however, all mites are host specific and will be discussed later.
'''Description''': The mite looks very similar in appearance to Chorioptes, being oval in shape with long legs, but is almost visible to the naked eye. It has pointed mouthparts and jointed pedicles which have suckers on the distal aspect.
'''Description''': The mite looks very similar in appearance to Chorioptes, being oval in shape with long legs, but is almost visible to the naked eye. It has pointed mouthparts and jointed pedicles which have suckers on the distal aspect.
'''Hosts''': Sheep, Cattle, Goats, Horse, Rabbit, Camelid
'''Life cycle''': Egg- Larvae- Nymph- Adult is confined to the skin surface. This life cycle takes around 10 days to complete. Adult female life expectancy is around one month and she lays 2-3 eggs per day, hence a mite population on an animal can expand rapidly. The mite can survive off the host and so transmission via housing and bedding is possible. Most transmission occurs from direct contact such as at markets or in livestock transporters.
This mite is found worldwide, but has been eradicated from Australia and New Zealand.
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== Pathogenesis ==
The mite feeds on exudate of lymph, skin cells and bacteria caused by a hypersensitivity reaction to mite faeces, from the host. This causes intense irritation leading to self trauma, crust and scale formation and inflammation.
The significance of this is due to the self trauma inflicted because of severe pruritus. This can lead to secondary infections (see later).
The disease is most prevalent in winter months, however does still occur in the summer, especially in sheep that have not been shorn.
== Clinical signs ==
*Mites are grossly visible
*Severe pruritus
*Evidence of self-trauma (loss, damage or staining of wool)
*Inflammation with exudate followed by a yellow crust
*Weight loss or reduced weight gain in young stock
*Microscopic examination for mites (low magnification)
== Diagnosis ==
*History and clinical signs
*Microscopic examination for mites (low magnification) to differentiate between Chorioptes and Psoroptes
<br>'''Control'''
<br>'''Control'''