3,326
edits
Changes
no edit summary
Mites are very small, on average under 0.3mm in length and for this reason often go unnoticed. They spend the majority of their life cycle '''on''' the host and cause '''mange'''.
Mites are very small, on average under 0.3mm in length and for this reason often go unnoticed. They spend the majority of their life cycle '''on''' the host and cause '''mange'''.
The body shows no segmentation but can be divided into two sections, the '''idiosoma''' and the '''gnathosoma'''. Adult and nymps have '''four''' pairs of legs, whereas larvae have only '''three''' pairs of legs.
The taxonomy of mites is complex as there are over 8 families. In this article the families are split according to their location on the host into sub-surface (burrowing) and surface (non-burrowing) mites.
The taxonomy of mites is complex as there are over 8 families. In this article the families are split according to their location on the host into sub-surface (burrowing) and surface (non-burrowing) mites.
*Terminal anus
*Terminal anus
*Male is about 250μm in length and the female about 400-430μm in length
'''Life Cycle'''
'''Life Cycle'''
*Causes severe pruritis in labaratory rodents
*Causes severe pruritis in labaratory rodents
*Burrowing activity causes biting, scratching and irritation
**Leads to inflammation, pruritis and alopecia
*Affected areas show acanthosis and hyperkeratosis
*Death can occur within 3-4 months of infection
*Transmission is due to close contact between between mother and offspring
===''Demodex''===
===''Demodex''===
*Known as feline scabies
*Known as feline scabies
*Also common ectoparasites of tropical bats
*Parasite of cats, rats, man and rabbits
*Parasite of cats, rats, man and rabbits
'''Recognition'''
'''Recognition'''
*Similar to ''Sarcotes''
*Similar to ''Sarcoptes''
*Less distinct angles on body surface
*Less distinct angles on body surface
*Females have suckers on legs one and two
*Females have suckers on legs one and two
*Females are about 225μm in length and males 150μm
*Anal opening is distinctly dorsal (not posterior)
'''Pathogenesis'''
'''Pathogenesis'''
*Causes dermatitis
*Causes dermatitis
*Burrowing of females damages keratinocytes leading to cytokine release
*Hypersensitivity reaction may occur
'''Diagnosis'''
'''Diagnosis'''
*Control
*Control
**Infestations are difficult to eliminate from a colony, although ivermectin is said to be effective.
**Infestations are difficult to eliminate from a colony, although ivermectin is said to be 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
'''Pathogenesis'''
*Economically important ectoparasite of sheep
*Causes '''sheep scab'''
**Wool loss, restlessness, biting, scratching of infested area and decreased productivity through a decreased weight gain
*Lesions most common on flanks, neck, back and shoulders
*Causes pruritic condition of cattle
===''Chorioptes bovis''===
===''Chorioptes bovis''===