Parasitic Mites (23) Flashcards
Begin E3
What are the differences between ticks and mites?
ticks: have a fused 2-pieced body plan
larger
have toothed hypostome
all are parasitic in all lifecycle stages
all ticks suck blood
mites: sometimes able to distinguish head and body regions
smaller
smooth hypostome
stigmata/spiracles vary in location
few are parasitic
What are the 3 morphological groups of mites?
mesostigmatid
astigmatid
prostigmatid
What is this? It is a [mite/tick]
mesostigmatid mite
How do mites cause disease to their hosts?
some suck blood
dermatosis, pierce skin, irritation and inflammation at bite site, sloughing skin, oozing lymph
facilitate secondary bacterial infections
Most mesostigmatid mites are ______, and some are parasitic
free-living
What is the morphology of mesostigmatid mites?
stigmata between 3rd and 4th pair of legs
What is the red roost mite of poultry?
dermanyssus gallinae
mesostigmatid
What mite is this? They are characterized by ______
dermanyssus gallinae
needle-like cheleceria
Where is dermanyssus gallinae found?
nests and bedding
— off the host except when feeding
vampire model
What are the consequences of dermanyssus gallinae?
anemia resulting from voracious blood sucking habits
zoonotic
people have contact with nests and are infested
What is the northern fowl mite called?
ornithonyssus sylvarium
(rodents: o. bacoti)
metastigmatids
What does ornithonyssus sp. cause?
annoyance, irritation, discomfort
people have contact with nests and are infested, almost with psychopathologic effects
How do you differentiate ornithonyssus sp. and dermanyssus gallinae?
ornithynyssus: mites are found on host and has scissor-like cbeleceria (not as long)
dermanyssus: off the host, needle-like
Identify the two different species
- ornithonyssus sp. - note scissor-like chelicera
- dermanyssus sp.
What are characteristics of astigmatid mites?
no stigmata
most are parasitic
What is a surface dwelling, astigmatid mite?
psoroptes ovis
chorioptes bovis
How does psoroptes ovis infect the host?
pierce skin with needle-like chellicerae
feed on oozing serum, serum begins to coagulate and form psoroptic scab
life cycle occurs on the host
What does psoroptes ovis lead to?
hair loss from rubbing and inflammation of dermis
How do you diagnose psoroptes ovis?
diagnosis by mites at edge of scab
reportable
What species is this?
psoroptes ovis
What species is this?
chorioptes bovis
What is the lifecycle of chorioptes bovis?
life cycle occurs on the host
surface-dwelling mite
A cow is observed to have mildly pruritic dermatitis on its back legs. What mite most likely caused this?
chorioptes bovis
Psoroptes sp. is [reportable / not reportable] and chorioptes is [reportable / not reportable]
reportable
not reportable
What are characteristics of otodectes cynotis?
surface-dwelling mite
lifecycle occurs in the outer ear canal on the host
does not pierce the skin
feeds on sloughed epidermal and epithelial debris
What species is this?
otodectes cynotis
What does otodectes cynotis induce?
superficial and mild pruritis
A dog is experiencing slightly itchy ears and black, waxy cerumen build-up in the ear. What likely caused this?
otodectes cynotis
What are sarcoptes spp.?
skin burrowing mites
chubby body with short legs
Where do you find sarcoptes spp.?
burrow into and tunnel under skin
pinna of ear, inguinal and hairless portions of the body
What does sarcoptes spp. cause?
pruritic, papular, erythema related to burrowing, defecation and eggs laid in tunnels
sarcoptic scab formed from oozing serum resulting from scratching and self-mutilation
hair loss from rubbing and inflammation of dermis extends suitable habitat for more mites
reportable
What is this?
sarcoptes scabiei var canis
What is the canine mange mite?
sarcoptes scabiei var canis
A stray dog is brought into the clinic looking like this. It is pruritic and has dermatitis. What likely caused this?
sarcoptes scabiei var canis
What is notoedres?
feline mange mite
What are characteristics of notoedres?
more often on surface in fur
easier to demonstrate on skin scrape
anus on terminal margin of ventral surface
A cat comes into the clinic and has mites around the anus. What likely is this?
notoedres
What are prostigmatid mites?
a diverse group of ranging from totally parasitic forms to free-living forms incidentally related to disease
diverse body shapes
What is demodectic mange?
localized
erythema usually around muzzle
alopecia around eyes and pinnae
immune naiive animals
generally self-limiting
prostigmatid
A dog comes in and has bony projections and red mange with dry, flaky skin. What likely caused this? What can it be confused with?
demodectic mange
not sarcoptes scabiei var canis
What is cheyletiella?
walking dandruff mite
massive palpal claws
Who is susceptible to cheyletiella?
dogs, cats, rabbits
What is this?
cheyletiella
What are chigger mites?
small, nearly microscopic nuisance associated with intense inflammatory responses to infestation
What component of chiggers are used to dissolve/liquefy host tissue for food?
salivary component
At what ages are chiggers parasitic?
only the larvae
How do you control and treat mite infestations?
macrocyclic lactones, etc
Contrast demodectic mange and sarcoptic mange
sarcoptic mange: at MARGIN of scab
This is [demodectic / sarcoptic] mange
sarcoptic
