17. mites Flashcards
— are microscopic ectoparsites
mites
what do mites feed on
blood, skin debris, lymph and sebaceous secretions
how are mites transmitted
direct prolonged contact
what are some symptoms of mites
dermatitis- mange
loss of blood and tissue
allergic reaction
vectors or intermediate hosts ( Anoplocephala, Monezia, Stilesia)
how do mites breathe
gas exchange by integument or stigmata
life cycle of a mite
3 nymph stages
all stages are on the host
4 types of burrowing mites
Sarcoptes
Notoedres
Knemidocoptes
Demodex
demodex
cigar shaped body
8 stumpy legs
striations on the abdomen
burrowing mite
Demodex folliculorum infect
humans
burrowing mite
Demodex phylloides infect
pigs
burrowing mites
where do demodex live
hair follicles and sebaceous glands
head downward
burrowing mites
symptoms of demodex
NOT itchy
localized:
paws and face with dry scales, mild alopecia and lesions
generalized:
dry/squamous- all over body thickened and crusty with marked alpopecia
wet/purulent/follicular- all over skin thickened, excoriated and red, marked alopecia, 2ndary bacterial infection- euthanasia
burrowing mite
red mange is caused by
demodex
burrowing mites
what does demodex look like
cigar shaped
8 legs
striation on the body
2 types of generalized demodecosis
dry/squamous- all over body thickened and crusty with marked alpopecia
wet/purulent/follicular- all over skin thickened, excoriated and red, marked alopecia, 2ndary bacterial infection- euthanasia
demodex- burrowing mites
Sarcoptes
burrowing mite (Sarcoptes, Notoedres, Knemidocoptes, Demodex)
what causes scabies
Sarcoptes scabiei var.
burrowing mite (Sarcoptes, Notoedres, Knemidocoptes, Demodex)
what does sarcoptes look like
short mouth
no eyes or stigmata
circular
stubby legs, 3th and 4th pair can’t be seen from the top
triangular scales in rows
1st two pair of pretarsi bears terminal suckers
on sarcoptes 1st pair of pretarsi are
terminal suckers
burrowing mite (Sarcoptes, Notoedres, Knemidocoptes, Demodex)
life cycle of Sarcoptes
14-21 days
females lay eggs in burrow(moulting pocket)- only one female per burrow
mating at surface
symptoms of Sarcoptes
itchy
skin lesions around head and ears
spread during suckling or mating
redness, alopecia
skin thickening
secondary infections
anorexia, blindness, impaired hearing
burrowing mite (Sarcoptes, Notoedres, Knemidocoptes, Demodex)