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*Sheep Scab
*Sheep Scab
*Psoroptic scabies
*Psoroptic scabies
*Psoroptosis
*Psoroptosis<br>
<br>
== Introduction ==
== Introduction ==
The mite is active in the keratin layer of the skin and has abrasive mouthparts. It feeds on exudate of lymph, skin cells and bacteria caused by a hypersensitivity reaction to antigenic mite faeces, by the host. This causes intense pruritus, leading to self trauma, crust and scale formation and inflammation.
The mite is active in the keratin layer of the skin and has abrasive mouthparts. It feeds on exudate of lymph, skin cells and bacteria caused by a hypersensitivity reaction to antigenic mite faeces, by the host. This causes intense pruritus, leading to self trauma, crust and scale formation and inflammation.
It is not only economically important to the sheep industry due to poor fleece quality and weight loss, but it can also pre-dispose to life-threatening condition such as Blowfly strike, as the blowflies find the damaged skin ideal for egg laying.
The disease is most prevalent in autumn and winter months, however does still occur in the summer, especially in sheep that have not been shorn.
The disease is most prevalent in autumn and winter months, however does still occur in the summer, especially in sheep that have not been shorn.
Psoroptic mange in sheep is a '''notifiable disease '''in the UK
Psoroptic mange in sheep '''used to be a ''''''notifiable disease '''in the UK, but has been de-regulated since 1992
== Clinical signs ==
== Clinical signs ==
*Skin scraping to microscopically identify mites (low magnification). Mites are found under scabs and in skin folds
*Skin scraping to microscopically identify mites (low magnification). Mites are found under scabs and in skin folds
<br>
== Treatment/ Control ==
Infestations are difficult to eliminate from a flock so a key factor in control is to not allow it to enter.
*New stock should be isolated for at least three weeks before mixing with the main flock
*Plunge dipping is curative and preventative<br>- dip must contain the Organophosphate diazinon or the Synthetic Pyrethroid cis-cypermethrin<br>- plunge dipping must last for at least one minute and the head should be fully submerged twice during this time<br>- the sheep must be kept moving when in the dip as the movement displaces air from in the fleece allwing better penetration
*Can treat with avermectins or milbemycins by injection<br>- only moxidectin has any prophylactic effect<br>- need two injections 7 days apart or one single dose (doramectin only) <br>
== Other species<br> ==
'''Cattle'''
Uncommon in the UK.
Affects withers mainly
Can be treated with avermectin, milbemycins or topical acaracides
'''Horse'''
Notifiable in the UK, but has not been recorded for many years
No licensed product for treatment of horses in the UK
'''Rabbits'''
'Ear canker mite' in rabbits
Externam auditory canal infection is often asymptomatic, but may cause scratching and head shaking behaviour
Can be treated with avermectin, milbemycins or topical acaracides
== References ==
Aitken, I.D, (2007) Diseases of Sheep fourth edition, Blackwell Publishing
Fox, M and Jacobs, D. (2007) Parasitology Study Guide Part 1: Ectoparasites, Royal Veterinary College
Hindson, J.C, (2002) Manual of Sheep Diseases second edition, Blackwell Publishing
Taylor, M.A, Coop, R.L, Wall, R.L, (2007) Veterinary Parasitology third edition, Blackwell Publishing
[[Category:To_Do_-_Kate]] [[Category:Integumentary_System_-_Mite_Infections]]
[[Category:To_Do_-_Kate]] [[Category:Integumentary_System_-_Mite_Infections]]