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Also Known as: '''''Sheep Scab - Psoroptic Scabies - Psoroptosis'''''

Also Known as: '''''Sheep Scab - Psoroptic Scabies - Psoroptosis'''''  

== Introduction  ==

== Introduction  ==

Other species of Psoroptes mite affect a variety of species including Cattle, Goats, Horse, Rabbit, Camelid, however, all mites are host specific.  

Other species of Psoroptes mite affect a variety of species including Cattle, Goats, Horse, Rabbit, Camelid, however, all mites are host specific.  

 

== Pathogenesis  ==

== Pathogenesis  ==

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.  

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.  

== Clinical signs  ==

== Clinical signs  ==

*Severe pruritus  

'''Severe pruritus and '''evidence of '''self-trauma '''(loss, damage or staining of wool) are the main signs to notice from within the herd. Once a closer inspection is made, inflammation and an exudate will be present on the skin and areas of yellow crust will also be present. In on-going cases,'''weight loss''' in adults, or redueced weight gain in growing animals, will be seen due to the irritation causing them to have a reduced feed intake. In some cases, secondary '''blowfly strike '''may by the first sign, when the sore traumatised skin has become a perfect breeding ground for the blowfly.

*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

*Secondary bacterial infection or '''Blowfly strike'''

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== Diagnosis  ==

== Diagnosis  ==

*History and clinical signs  

History and clinical signs often enough to make presumptive diagnosis. Skin scraping to microscopically identify mites (low magnification) should be peformed. 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

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== Treatment/ Control  ==

== Treatment/ Control  ==

Infestations are difficult to eliminate from a&nbsp;flock so a key factor in control is to not allow it to enter.  

Infestations are difficult to eliminate from a&nbsp;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.  

 

*New stock should be isolated for at least three weeks before mixing with the main flock

Psoroptes can be treated with avermectins or milbemycins by injection, but only moxidectin has any prophylactic effect;&nbsp;need two&nbsp;injections 7 days apart or one single dose (doramectin only).&nbsp;<br>

*Can treat with avermectins or milbemycins by injection<br>- only moxidectin has any prophylactic effect<br>- need two&nbsp;injections 7 days apart or one single dose (doramectin only)&nbsp;<br>

== Other species<br> ==

== Other species<br> ==

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'''Rabbits''' [[Mites – Rabbit#Psoroptiasis| 'Ear canker mite']] in rabbits caused by ''[[Psoroptes cuniculi]]''

'''Rabbits''' [[Mites – Rabbit#Psoroptiasis|'Ear canker mite']] in rabbits caused by ''[[Psoroptes cuniculi]]''  

Externam auditory canal infection is often asymptomatic, but may cause scratching and head shaking behaviour  

Externam auditory canal infection is often asymptomatic, but may cause scratching and head shaking behaviour  

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== References  ==

== References  ==

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[[Category:To_Do_- Kate]][[Category:Integumentary_System_-_Mite_Infections]]

[[Category:To_Do_-_Review]] [[Category:Integumentary_System_-_Mite_Infections]]