Ectoparasites Flashcards
(45 cards)
Sarcoptes scabiei
Scabies mite
Sarcoptes scabei var hominis
human mite
Notoedres cati
tunneling mite
ascariasis
infestation of mites (or ticks)
sarcoptic acariasis
infestation of S. scabei
what are the four developmental stages of S. scabei
egg, larva, nymph, adult
adult male and female mites are found on the skin surface, after copulation, the female mite will burrow into the skin, tunnel w/in the epidermis and layer her eggs in tunnel shaft
As the eggs hatch, they will release larvae and make new tunnels which causes the pruritis
what is used to diagnosis sarcoptic acariasis?
superficial skin scraping w/ scalpel blade
mineral oil
Otodectes cynotis
ear mite
dogs, cats, ferrets
life cycle of otodectes cynotis
3 weeks
female mite lays 5 eggs/day in the ear –> mature into larvae w/in 4 days then hatch into nymphs –> 2 developmental stages –> adults
demodex sp
skin mite
mange
life cycle of demodex spp
mite dwells in hair follicles and sebacecous glands
produces localized or genralized alopecia
NONpruritic unless complicated by secondary bacterial inection
can spread via intimate body contact between dam and puppies
how to diagnosis demodex
deep skin scraping
plucked hair
mineral oil
cheyletiella parasitivorax
walking dandruff mite
cheyletiella yasguri
seen in dogs w/ lesions
cheyletiella blakei
seen in cats that develop miliary dermatitis
life cycle of cheyletiella
21 days
5 stages: egg, prelarva, first and second nymphs, adult
female hatches eggs to hair, where they hatch into 6 legged prelarvae that then mature into 8 leg nymphs and then 8 leg adults
what species is extremely contagious?
cheyletiella
can be transferred to humans as well
Trombicular species
chiggers, jiggers, red bugs
what stage of the chigger is parasitic?
6 legged larvae stage
they are found attached to the skin of the infected host, where they feed before dropping off
they DO NOT BURROW into the skin
they will inject their saliva and liquefy the host’s tissues –> causes skin irritation
what are the four developmental stages of Trombicula (Chiggers)
4 stages:
egg
6 legged larva
8 legged nymph
8 legged adult
NOT ZOONOTIC
What are the two categories of ticks?
hard shell ticks (Ioxididae)
soft shell ticks (Argasidae)
Dermancentor, Rhipcephalus, Amblyomma, Ixodes
ticks, dog ticks, spotted tick
poikilothermic
having body temp that changes w/ outside temp
what are the four developmental stages of ticks?
egg
larva
nymph
adult
after copulation and incubation, the adult female tick will drop off of the host and lay her eggs in the external environment where they hatch, produce 6 legged larvae (SEED TICKS). The larvae will crawl up a blade of grass and attach itself to the first host and then feed on the host before dropping off and then molting into the 8 legged nymph. The nymph crawls up a blade of grass and attaches second host . After feeding, will then drop off and then molt into FINAL DEVELOPMENTAL stage which is the 8 legged adult stage and then crawl up a blade of grass and then jumps onto another host
