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| | '''[[Burrowing Mites]]''' | | '''[[Burrowing Mites]]''' |
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| − | ==Non-Burrowing Mites==
| + | '''[[Non-Burrowing Mites]] |
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| − | *Live on the skin surface
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| − |
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| − | *Feed on either skin scales and tissue or suck blood
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| − |
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| − |
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| − | ===''Psoroptes''===
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| − | *Causes [[Parasitic skin infections - Pathology#Psoroptic mites|psoroptic skin infestation]]
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| − |
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| − | '''Recognition'''
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| − | *Oval shaped
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| − |
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| − | *Long legs
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| − |
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| − | *Funnel shaped suckers on '''segmented''' pedicels
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| − |
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| − | *1-2mm in length
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| − |
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| − |
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| − | '''Life cycle'''
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| − | *Confined to skin surface
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| − |
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| − | *Feed on serous exudate by siphoning
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| − |
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| − | *Adult female can lay up to 100 eggs during her life time (1 month)
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| − |
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| − | *10 day life cycle
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| − | *2 nymphal stages
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| − |
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| − |
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| − | ====''Psoroptes cuniculi''====
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| − | *Parasite of rabbits
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| − | *Common among conventional rabbits
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| − |
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| − | *Transmitted via contact
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| − | *Adapted to living in an aural environment
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| − |
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| − | '''Pathogenesis'''
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| − | *The ears are painful and intensely pruritic
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| − |
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| − | *Affected rabbits shake their heads and scratch their ears
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| − |
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| − | *The inner surfaces of the pinnae are covered with brown, scaly, fetid material, and the skin beneath is raw
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| − |
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| − | *Mites are grossly visible
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| − |
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| − | *Histologically, there is chronic erosive and proliferative eosinophilic dermatitis
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| − | **The mites are non-burrowing and thus are found only in the exudate, not in the tissue
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| − |
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| − |
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| − | '''Diagnosis'''
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| − | *Microscopic examination for mites (low magnification)
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| − |
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| − | *Appearance
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| − |
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| − |
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| − | '''Control'''
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| − | *Infestations are difficult to eliminate from a colony
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| − | **Ivermectin is usually effective
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| − |
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| − |
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| − | ====''Psoroptes ovis''====
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| − |
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| − | *Adult females are large mites at 750μm in length
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| − |
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| − | *Males identified by copulatory suckers and paired posterior lobes
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| − |
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| − | *Males attach to deutonymphs (second moult after larval stage) in a process called '''copula'''
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| − | **Males remain in copula until females moult for the last time
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| − | **Copulation occurs
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| − |
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| − | *Life cycle last '''14 days'''
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| − |
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| − | *Transmitted by direct contact between sheep
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| − |
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| − | *Indirect transmission can also occur
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| − | '''Pathogenesis'''
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| − | *Economically important ectoparasite of sheep
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| − |
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| − | *Causes '''sheep scab'''
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| − | **Wool loss, restlessness, biting, scratching of infested area and decreased productivity through decreased weight gain
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| − | **Usually seen in '''late autumn''' and '''early winter''' (although may also occur in late summer)
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| − | **Population numbers decline after shearing due to a change in the micro-climate, then build up again as the fleece grows
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| − | **'''Notifiable in UK'''
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| − |
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| − | *Mites found under scabs and in skin folds
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| − | *Lesions most common on flanks, neck, back and shoulders
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| − |
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| − | *Causes pruritic condition of cattle
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| − | *Active in keratin layer
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| − |
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| − | *Mouthparts abrade the skin
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| − | *Antigenic material in mite faeces can lead to hypersensitivity reactions
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| − | '''Diagnosis'''
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| − | *Skin scraping
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| − | *KOH added
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| − | *Warm slide over a bunsen flame
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| − | *Examine under a microscope
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| − |
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| − | '''Treatment'''
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| − | *Sheep
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| − | **Plunge dipping; no less than 1 minute and must dip head at lease once
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| − | **Can treat with avermectins or milbemycins by injection
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| − |
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| − | *Cattle, horses and rabbits
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| − | **No licensed product for horses in the UK
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| − | **Cattle and rabbits can be treated with avermectins, milbemycins or topical acaricides
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| − |
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| − | ===''Chorioptes bovis''===
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| − |
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| − | *These cause [[Parasitic skin infections - Pathology#Chorioptic mites|parasitic skin infestation]]
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| − |
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| − | *Surface parasite of horses and cattle
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| − | *Less pathogenic than ''Psoroptes''
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| − | **Mouthparts cannot pierce the skin
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| − |
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| − | *Life cycle takes '''3 weeks'''
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| − | '''Recognition'''
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| − | *Oval body
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| − | *Long legs
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| − | *Cup shaped suckers on '''unsegmented''' pedicels
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| − | *Females about 300μm in length
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| − | '''Pathogenesis'''
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| − | *Chorioptic mange
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| − | **Often seen in rough-legged horses with heavy feathering
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| − | **Induce crusty skin and lesions below the hocks and knees
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| − | *Mild condition in cattle
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| − | **Rubbing and scratching
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| − | **Hide damage
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| − | **Usually affects the base of the tail, perineum and udder
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| − | *Usually found on legs of sheep
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| − | **Mild condition
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| − | ===''Otodectes cynotis''===
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| − | *Causes [[Parasitic skin infections - Pathology#Otodectic mites|otodectic skin infestation]]
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| − | *Commonest mange of dogs and cats in the world
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| − | *Inhabits the inner ear
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| − | *Also found in the fox and the ferret
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| − | *Closed keratinous bars ('''apodemes''') on ventral surface
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| − | *Life cycle takes '''3 weeks'''
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| − | *Feeds on ear debris
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| − | '''Pathogenesis'''
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| − | *The majority of cats harbour the mites, however only a few show symptoms
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| − | **Transmission occurs whilst kittens are suckling
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| − | *Common cause of [[Otitis Externa - Small Animal|otitis externa]] in dogs
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| − | *Brown waxy exudate produced
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| − | *Can lead to secondary infection
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| − |
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| − | *Clinical signs are apparent
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| − | **Head shaking
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| − | **Ear scratching
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| − | **Aural haematomata
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| − | '''Treatment'''
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| − | *Acaracidal ear drops
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| − | **Massage base of ear to disperse drops after treatment
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| − | *Most treatments need to be repeated in 10-14 days to kill newly hatched mites
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| − | *Selamectin can be used as a spot-on treatment
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| − | **Prolonged duration of action
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| − | *Treat all in-contact animals
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| − | **These may be asymptomatic carriers
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| − | ===''Cheyletiella spp.''===
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| − | *Surface mite of cats and dogs
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| − | *Also found on humans and rabbits
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| − | **''C.yasguri'' (dogs)
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| − | **''C.blakei'' (cats and humans)
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| − | **''C.parasitivorax'' (rabbits)
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| − | *Causes [[Parasitic skin infections - Pathology#Cheyletiellosis|parasitic skin infestation]]
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| − | '''Recognition'''
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| − | *Waisted body
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| − | *Claw like palps on head
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| − | *Combs at ends of legs
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| − | '''Pathogenesis'''
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| − | *Highly contagious
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| − | *Mild pathogenesis
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| − | *Causes very scaly dermatitis
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| − | *Can be transferred to humans
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| − | '''Diagnosis'''
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| − | *Clinical signs
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| − | **Excess scurf
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| − | *Brush scurf onto dark paper
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| − | **'Walking dandruff' as mites will move when present in large numbers
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| − | *Skin scrapings
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| − | *Hair pluckings from scaly areas
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| − | **Eggs may be present
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| − | ===''Dermanyssus gallinae''===
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| − | *Red mite of poultry
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| − | *Spends most of time '''off''' the host
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| − | **Adults and nymphs visit poultry at night to feed
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| − | *Life cycle takes '''1 week'''
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| − | *Adults can survive several months without feeding so reservoirs can build up
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| − |
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| − | '''Appearance'''
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| − | *Spider like mite with long legs
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| − | *White or grey
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| − | **Becomes red when engorged with blood after feeding
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| − | *Few hairs on body
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| − | *Hooks on legs
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| − | '''Pathogenesis'''
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| − | *Blood sucking mite
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| − | *Lesions usually found on the breast and legs
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| − | *Irritation, restlessness, decrease in egg production
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| − | *Anaemia can result if mites are present in large numbers
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| − | *Newly hatched chicks can rapidly die if infested
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| − | '''Treatment'''
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| − | *Acaricide
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| − | *Environmental treatment
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| − | *Remove wild bird nests
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| − | ===''Ornithonyssus''===
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| − | *Also called the Northern mite or Northern feather mite
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| − | *Closely related to ''Dermanyssus''
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| − | *Hairy
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| − | *Spends entire life cycle '''on''' the host
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| − | *Occurs in caged birds and poultry
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| − | *Causes feathers to become matted and severe scabbing can develop
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| − | **Scabs particularly seen around the vent
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| − | *Decreases egg production
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| − | *Grey or black discolouration of feathers when large numbers of mites are present
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| − | ===''Trombicula autumnalis''===
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| − | *Causes [[Parasitic skin infections - Pathology#Trombiculidiasis|parasitic skin infestation]]
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| − | *Also called the harvest mite
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| − | *Not host-specific
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| − | **Will parasitise any animal, including humans
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| − | *Only the larval stage is parasitic
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| − | **Nymphal and adult stages are free-living in the soil
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| − | *Mite numbers are highest in late summer in temperate climates
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| − | **Mite numbers are constant all year in tropical regions
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| − | '''Recognition'''
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| − | *Six legs
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| − | *Bright orange in colour
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| − | *Hairy
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| − | *No spiracles
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| − | **Breath through cuticle
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| − |
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| − | '''Pathogenesis'''
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| − | *Larvae insert mouthparts into skin and inject cytolytic enzymes
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| − | *Feed on partly digested host tissue
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| − | *Causes irritation
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| − | *Can cause a hypersensitivity reaction
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| − | *Mites found on head, ears and flanks of pets
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| − | *Mites found on face and limbs of grazing animals (depending upon host height)
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| − | '''Control'''
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| − | *Very difficult; try to restrict access of animals to 'hot-spot' areas
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| − | '''Treatment'''
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| − | *Fipronil spray applied to affected areas
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| − | ===''Leporacarus''===
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| − | *Known as the rabbit fur mite
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| − | *Found on rabbits (domestic and wild) and on hares
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| − | *Common
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| − | *Clings to individual hairs
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| − | *Feeds on sebaceous secretions and skin debris
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| − | *Non-pathogenic
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| − | *May cause dermatitis in humans handling infected animals
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