Parasitic Mites Flashcards
how mites cause disease to host
some suck blood and cause anemia
dermatosis, irritation & inflammation @ bite, oozing lymph
–itchy, self mutilation
facilitate secondary bacterial infections
Mesostigmatid mites
stigmata between 3rd and 4th pair of legs
legs evenly spaces in anterior 1/2
claws on end of tarsi
most free-living, some parasitic
dermanyssus gallinane
red roost mite in poultry
found in nests and bedding
-vampire model, OFF HOST unless feeding
anemia results from blood sucking habits
zoonotic
DX: needle-like cheleceria
ornithonyssus sp.
poultry and rodents
found ON HOST
annoyance, irritations, discomfort
DX: scissor-like cheleceria
astigmatid mites
no stigmata bc respiration cutaneous
2n and 3rd pair of legs widely separated
suckers on end of tarsi
most are parasitic (surface dwelling or skin burrowing)
psoroptes ovis
surface dwelling mite
ON HOST
pierce skin w needle-like chellicerae, feed on oozing serum
psoroptic scab formed from coagulated serum
hair loss from rubbing and inflammation of dermis
DX: mites @ edge of scab
suckers on long pedicles at end of tarsi
REPORTABLE
chorioptes bovis
surface dwelling mite
ON HOST
does not pierce skin
feeds on sloughed epidermal/ epidermal debris
superficially mildly pruritic, flaky dermatitis
self-limiting
DX: mites on host in areas of dermatitis
short suckers at end of tarsi
NOT REPORTABLE
otodectes cynotis
surface dwelling mite
life cycle in outer ear canal on host
does not pierce skin
feeds on sloughed epidermal/ epidermal debris
superficially mildly pruritic
DX: ear swab of outer ear canal and observation of mites
suckers at end of leg
black, waxy cerumen (droppings)
sarcoptes spp
skin burrowing mites
cubby body w short legs
ON HOST
burrow into and tunnel under the skin
**on hair less portions of body
Feed on serum, fluids, host proteins
sarcoptic scab formed oozing serum resulting from self mutilation
-hair loss from rubbing and inflammation of dermis extends suitable habitat for more mites
DX: deep skin scape @ edge of scab
REPORTABLE
sarcoptes spp pruitic, papular, erythema related to
defecation and eggs laid in tunnels
sarcoptes scabiei var canis
canine mange mite
burrowing
-hard to demonstrate so deep scrape crusty lesion
alopecia inguinal areas
pineal/pedal reflex
–scratch underside of ear flap
anus on ventral side
notoedres
feline mange mite
often on surface fur
-easier to demonstrate on skin scrape
anus on terminal margin of ventral surface
ear mite treatment
clean ears 1st
Milbemite
scabies treatment
revolution @ monthly labeled dose
demodectic mange
localized
erythema around muzzle
alopecia around eyes and pinnae
immune naaive animals can obtain from nursing on mother
self limiting
Demodectic mange from secondary
generalized
red mange w/ dry flaky skin
erythema around elbows and boney projections
alopecia around eyes and pinnae
immuno-compromised animals
**must identify underlying condition
**difficult to control, impossible to cure
cheyletiella
walking dandruff mite
massive palpal claws
DX: brushing fur
-KOH digestion w/ sugar floatation
in dogs, cats rabbits
zoonotic potential
chigger mites
small, nearly microscopic
intense inflammatory response
salivary component used to dissolve/ liquefy host tissue for food
-necrotizes skin forms stylostome feeding tube
-head attached to host for duration of feeding
only larvae parasitic
chigger mites larvae
6 legs
bright orange
ears of cats and dogs
treatment/ control of mites
macrocyclic lactones
(IVM, moxidectin)
