Demodex Flashcards
Demodex mites transmission
from mom to pups when they’re 1-3 days old
normal in low numbers in post-natal dogs
What makes mites a disease state v. healthy state
abnormal proliferation of mites
Pathogenesis of demodex
- deficient immune response
- genetic, juvenile onset
- immunosupressed
- bacterial folliculitis (both demodex and staph live in hair follicle so they go hand in hand)
is demodex contagious or zoonotic?
nope
clinical signs of demodex
papules/pustules, erythema
alopecia (patchy bc folliculitis) hyperpigmentation
scaling, crusting
**comedones (plugged hair follicles)
diagnosis of demodex
deep skin scrape hair plucks (in area you don't want to plug, eye) biopsy (sharpei (thick skin), scar tissue, pododermatitis) shows dilated hair follicle full of mites
different ages for juvenile onset of demodicosis for different breeds
small breeds <12 mo
large breeds <18 mo
giant breeds <24 mo
demodex and _____ are closely related
staphlococcus (both live in hair follicle)
benign demodicosis
mites in one area based on 5 deep skin scrape
= localized
*can be bred
generalized v. localized
localized is benign, typically won’t recur
generalized
progression of localized demodicosis
90% will clear spontaneously (in 6-12 weeks)
10% will generalize
Which demodicosis generally has a good prognosis
localized juvenile onset
therapy juvenile localized demodex?
- benign neglect
- abx (esp. if pustular)
- topical: 2% mupirocin, benzoyl peroxide gel,
- systemic if needed - de-worming, good diet, HW rx
Don’t give to tx localized juvenile demodicosis
steroids
anti-mite therapy
(will predispose to relapse)
why wouldn’t you treat localized demodecosis with miticides?
- you want to know if it will become generalized
2. to prevent unnecessary medical treatment
recheck in
2-4 weeks to see if it becomes generalized
generalized demodicosis
2+ regions, typically when found on feet is generalized
juvenile onset generalized
should be neutered because its genetic
50% will clear
50% will need anti-mite tx (95% of those will resolve 5% will keep relapsing)
adult onset generalized
underlying immunosuppression
treat cause
treatments to kill mites
*amitraz!
ivermectin
milbemycin
Amitraz
only FDA approved tx
- clip hair short and bathe with benzoyl peroxide to open the follicle before dipping (let air dry)
- dip weekly
- not used often anymore
- toy breeds, immunosuppresed at risk for toxicity - sedation
- avoid with diabetes
Ivermectin
off label
400-600mcg/kg (.4-.6ml/kg) daily (no collies, shelties)
- build up dose slowly!
treat generalized demodex until
several negative scrapes
Moxidectin
advantage multi
- weekly, systemic absorbtion
