| Line 15: |
Line 15: |
| | '''[[Burrowing Mites]]''' | | '''[[Burrowing Mites]]''' |
| | | | |
| − | ==Non-Burrowing Mites==
| + | '''[[Non-Burrowing Mites]] |
| | | | |
| − | *Live on the skin surface
| |
| − |
| |
| − | *Feed on either skin scales and tissue or suck blood
| |
| − |
| |
| − |
| |
| − | ===''Psoroptes''===
| |
| − |
| |
| − | *Causes [[Parasitic skin infections - Pathology#Psoroptic mites|psoroptic skin infestation]]
| |
| − |
| |
| − |
| |
| − | '''Recognition'''
| |
| − | *Oval shaped
| |
| − |
| |
| − | *Long legs
| |
| − |
| |
| − | *Funnel shaped suckers on '''segmented''' pedicels
| |
| − |
| |
| − | *1-2mm in length
| |
| − |
| |
| − |
| |
| − | '''Life cycle'''
| |
| − | *Confined to skin surface
| |
| − |
| |
| − | *Feed on serous exudate by siphoning
| |
| − |
| |
| − | *Adult female can lay up to 100 eggs during her life time (1 month)
| |
| − |
| |
| − | *10 day life cycle
| |
| − |
| |
| − | *2 nymphal stages
| |
| − |
| |
| − |
| |
| − | ====''Psoroptes cuniculi''====
| |
| − |
| |
| − | *Parasite of rabbits
| |
| − |
| |
| − | *Common among conventional rabbits
| |
| − |
| |
| − | *Transmitted via contact
| |
| − |
| |
| − | *Adapted to living in an aural environment
| |
| − |
| |
| − |
| |
| − | '''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 ovis''====
| |
| − |
| |
| − | *Adult females are large mites at 750μm in length
| |
| − |
| |
| − | *Males identified by copulatory suckers and paired posterior lobes
| |
| − |
| |
| − | *Males attach to deutonymphs (second moult after larval stage) in a process called '''copula'''
| |
| − | **Males remain in copula until females moult for the last time
| |
| − | **Copulation occurs
| |
| − |
| |
| − | *Life cycle last '''14 days'''
| |
| − |
| |
| − | *Transmitted by direct contact between sheep
| |
| − |
| |
| − | *Indirect transmission can also occur
| |
| − |
| |
| − |
| |
| − | '''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
| |
| − |
| |
| − | ===''Chorioptes bovis''===
| |
| − |
| |
| − | *These cause [[Parasitic skin infections - Pathology#Chorioptic mites|parasitic skin infestation]]
| |
| − |
| |
| − | *Surface parasite of horses and cattle
| |
| − |
| |
| − | *Less pathogenic than ''Psoroptes''
| |
| − | **Mouthparts cannot pierce the skin
| |
| − |
| |
| − | *Life cycle takes '''3 weeks'''
| |
| − |
| |
| − |
| |
| − | '''Recognition'''
| |
| − | *Oval body
| |
| − |
| |
| − | *Long legs
| |
| − |
| |
| − | *Cup shaped suckers on '''unsegmented''' pedicels
| |
| − |
| |
| − | *Females about 300μm in length
| |
| − |
| |
| − |
| |
| − | '''Pathogenesis'''
| |
| − | *Chorioptic mange
| |
| − | **Often seen in rough-legged horses with heavy feathering
| |
| − | **Induce crusty skin and lesions below the hocks and knees
| |
| − |
| |
| − | *Mild condition in cattle
| |
| − | **Rubbing and scratching
| |
| − | **Hide damage
| |
| − | **Usually affects the base of the tail, perineum and udder
| |
| − |
| |
| − | *Usually found on legs of sheep
| |
| − | **Mild condition
| |
| − |
| |
| − |
| |
| − | ===''Otodectes cynotis''===
| |
| − |
| |
| − | *Causes [[Parasitic skin infections - Pathology#Otodectic mites|otodectic skin infestation]]
| |
| − |
| |
| − | *Commonest mange of dogs and cats in the world
| |
| − |
| |
| − | *Inhabits the inner ear
| |
| − |
| |
| − | *Also found in the fox and the ferret
| |
| − |
| |
| − | *Closed keratinous bars ('''apodemes''') on ventral surface
| |
| − |
| |
| − | *Life cycle takes '''3 weeks'''
| |
| − |
| |
| − | *Feeds on ear debris
| |
| − |
| |
| − |
| |
| − | '''Pathogenesis'''
| |
| − | *The majority of cats harbour the mites, however only a few show symptoms
| |
| − | **Transmission occurs whilst kittens are suckling
| |
| − |
| |
| − | *Common cause of [[Otitis Externa - Small Animal|otitis externa]] in dogs
| |
| − |
| |
| − | *Brown waxy exudate produced
| |
| − |
| |
| − | *Can lead to secondary infection
| |
| − |
| |
| − | *Clinical signs are apparent
| |
| − | **Head shaking
| |
| − | **Ear scratching
| |
| − | **Aural haematomata
| |
| − |
| |
| − |
| |
| − | '''Treatment'''
| |
| − | *Acaracidal ear drops
| |
| − | **Massage base of ear to disperse drops after treatment
| |
| − |
| |
| − | *Most treatments need to be repeated in 10-14 days to kill newly hatched mites
| |
| − |
| |
| − | *Selamectin can be used as a spot-on treatment
| |
| − | **Prolonged duration of action
| |
| − |
| |
| − | *Treat all in-contact animals
| |
| − | **These may be asymptomatic carriers
| |
| − |
| |
| − |
| |
| − | ===''Cheyletiella spp.''===
| |
| − |
| |
| − | *Surface mite of cats and dogs
| |
| − |
| |
| − | *Also found on humans and rabbits
| |
| − | **''C.yasguri'' (dogs)
| |
| − | **''C.blakei'' (cats and humans)
| |
| − | **''C.parasitivorax'' (rabbits)
| |
| − |
| |
| − | *Causes [[Parasitic skin infections - Pathology#Cheyletiellosis|parasitic skin infestation]]
| |
| − |
| |
| − |
| |
| − | '''Recognition'''
| |
| − | *Waisted body
| |
| − |
| |
| − | *Claw like palps on head
| |
| − |
| |
| − | *Combs at ends of legs
| |
| − |
| |
| − |
| |
| − | '''Pathogenesis'''
| |
| − | *Highly contagious
| |
| − |
| |
| − | *Mild pathogenesis
| |
| − |
| |
| − | *Causes very scaly dermatitis
| |
| − |
| |
| − | *Can be transferred to humans
| |
| − |
| |
| − |
| |
| − | '''Diagnosis'''
| |
| − | *Clinical signs
| |
| − | **Excess scurf
| |
| − |
| |
| − | *Brush scurf onto dark paper
| |
| − | **'Walking dandruff' as mites will move when present in large numbers
| |
| − |
| |
| − | *Skin scrapings
| |
| − |
| |
| − | *Hair pluckings from scaly areas
| |
| − | **Eggs may be present
| |
| − |
| |
| − |
| |
| − | ===''Dermanyssus gallinae''===
| |
| − |
| |
| − | *Red mite of poultry
| |
| − |
| |
| − | *Spends most of time '''off''' the host
| |
| − | **Adults and nymphs visit poultry at night to feed
| |
| − |
| |
| − | *Life cycle takes '''1 week'''
| |
| − |
| |
| − | *Adults can survive several months without feeding so reservoirs can build up
| |
| − |
| |
| − |
| |
| − | '''Appearance'''
| |
| − | *Spider like mite with long legs
| |
| − |
| |
| − | *White or grey
| |
| − | **Becomes red when engorged with blood after feeding
| |
| − |
| |
| − | *Few hairs on body
| |
| − |
| |
| − | *Hooks on legs
| |
| − |
| |
| − |
| |
| − | '''Pathogenesis'''
| |
| − | *Blood sucking mite
| |
| − |
| |
| − | *Lesions usually found on the breast and legs
| |
| − |
| |
| − | *Irritation, restlessness, decrease in egg production
| |
| − |
| |
| − | *Anaemia can result if mites are present in large numbers
| |
| − |
| |
| − | *Newly hatched chicks can rapidly die if infested
| |
| − |
| |
| − |
| |
| − | '''Treatment'''
| |
| − | *Acaricide
| |
| − |
| |
| − | *Environmental treatment
| |
| − |
| |
| − | *Remove wild bird nests
| |
| − |
| |
| − | ===''Ornithonyssus''===
| |
| − |
| |
| − | *Also called the Northern mite or Northern feather mite
| |
| − |
| |
| − | *Closely related to ''Dermanyssus''
| |
| − |
| |
| − | *Hairy
| |
| − |
| |
| − | *Spends entire life cycle '''on''' the host
| |
| − |
| |
| − | *Occurs in caged birds and poultry
| |
| − |
| |
| − | *Causes feathers to become matted and severe scabbing can develop
| |
| − | **Scabs particularly seen around the vent
| |
| − |
| |
| − | *Decreases egg production
| |
| − |
| |
| − | *Grey or black discolouration of feathers when large numbers of mites are present
| |
| − |
| |
| − |
| |
| − | ===''Trombicula autumnalis''===
| |
| − |
| |
| − | *Causes [[Parasitic skin infections - Pathology#Trombiculidiasis|parasitic skin infestation]]
| |
| − |
| |
| − | *Also called the harvest mite
| |
| − |
| |
| − | *Not host-specific
| |
| − | **Will parasitise any animal, including humans
| |
| − |
| |
| − | *Only the larval stage is parasitic
| |
| − | **Nymphal and adult stages are free-living in the soil
| |
| − |
| |
| − | *Mite numbers are highest in late summer in temperate climates
| |
| − | **Mite numbers are constant all year in tropical regions
| |
| − |
| |
| − |
| |
| − | '''Recognition'''
| |
| − | *Six legs
| |
| − |
| |
| − | *Bright orange in colour
| |
| − |
| |
| − | *Hairy
| |
| − |
| |
| − | *No spiracles
| |
| − | **Breath through cuticle
| |
| − |
| |
| − |
| |
| − | '''Pathogenesis'''
| |
| − | *Larvae insert mouthparts into skin and inject cytolytic enzymes
| |
| − |
| |
| − | *Feed on partly digested host tissue
| |
| − |
| |
| − | *Causes irritation
| |
| − |
| |
| − | *Can cause a hypersensitivity reaction
| |
| − |
| |
| − | *Mites found on head, ears and flanks of pets
| |
| − |
| |
| − | *Mites found on face and limbs of grazing animals (depending upon host height)
| |
| − |
| |
| − |
| |
| − | '''Control'''
| |
| − | *Very difficult; try to restrict access of animals to 'hot-spot' areas
| |
| − |
| |
| − |
| |
| − | '''Treatment'''
| |
| − | *Fipronil spray applied to affected areas
| |
| − |
| |
| − |
| |
| − | ===''Leporacarus''===
| |
| − |
| |
| − | *Known as the rabbit fur mite
| |
| − |
| |
| − | *Found on rabbits (domestic and wild) and on hares
| |
| − |
| |
| − | *Common
| |
| − |
| |
| − | *Clings to individual hairs
| |
| − |
| |
| − | *Feeds on sebaceous secretions and skin debris
| |
| − |
| |
| − | *Non-pathogenic
| |
| − |
| |
| − | *May cause dermatitis in humans handling infected animals
| |
| | | | |
| | | | |